Files
Evan 102b506b0b fix(agents,hands): per-agent/per-hand mcp_servers / skills allowlists (#87) (#92)
All 32 agent manifests and 17 hands shipped with empty mcp_servers /
skills lists, which the kernel interprets as "no filter" — every
globally-configured MCP server's tools and every installed skill get
injected into the prompt on every LLM call. On a typical instance (9
MCP servers, ~85 MCP tools + ~82 built-in tools) that's ~50k input
tokens per turn spent on definitions the agent never uses.

Changes
-------

32 agents/*/agent.toml:
  - mcp_servers: 1-4 per agent. memory wherever state persists across
    turns; fetch / exa-search / brave-search only where the prompt
    actually calls for web; git / github / filesystem on engineering
    agents; gmail / google-calendar / linear / jira on productivity
    agents whose prompts mention them.
  - skills: per-role allowlist driven by what the system_prompt names
    (e.g. coder → rust/python/typescript/git/shell-scripting; devops-
    lead → docker/kubernetes/terraform/ansible/ci-cd/helm/prometheus/
    sysadmin). Generalists (assistant) keep skills = [] (see "Open
    items" below).
  - skills_disabled = true on the four short-conversational agents
    (hello-world, recipe-assistant, health-tracker, home-automation).
    Their system prompts never instruct the LLM to consult any skill,
    so loading all 60 was pure waste. They also drop the explicit
    max_history_messages override and inherit the kernel default (60).
  - max_history_messages tiered by workload shape:
      60  short conversational (hello-world, recipe, health-tracker,
          home-automation) — inherits the rising kernel default
          (`DEFAULT_MAX_HISTORY_MESSAGES = 60`); no override needed.
      60  single-turn task agents (writer, translator, doc-writer,
          email-assistant, customer-support, sales-assistant, recruit-
          er, social-media, personal-finance, tutor, travel-planner,
          meeting-assistant, ops, devops-lead, planner) — explicit
          override at the same value to lock the cap if the kernel
          default moves again.
      80  multi-step / tool-heavy (coder, debugger, architect, code-
          reviewer, test-engineer, security-auditor, analyst, data-
          scientist, academic-researcher, researcher, legal-assistant)
      120 coordinators (assistant, orchestrator) — long multi-agent
          sessions where prompt-cache continuity is critical
    All values sit at or above the kernel default. Pinning lower
    would thrash the prompt cache (the failure mode #91 fixed for
    the creator hand by *raising* the cap, not lowering it).

17 hands/*/HAND.toml:
  - hand-level mcp_servers / skills now declared on every hand, so
    every [agents.*] inside inherits a sensible allowlist.
  - skills_disabled = true placed on each [agents.*] inside clip and
    creator (pure media pipelines that don't benefit from any skill).
    HandDefinitionRaw in librefang-hands does NOT have a top-level
    skills_disabled field — declaring it at the hand top level would
    be silently dropped by serde, so the setting must live on the
    AgentManifest of each sub-agent role.
  - devteam: expand existing mcp_servers = ["github"] to include
    memory / git / filesystem; populate skills with the expected
    dev-team expertise (replacing the placeholder skills = []).
  - wiki: replace placeholder mcp_servers = [] with [memory, fetch,
    filesystem]. Hand-level skills stays [].
  - lead: hand-level skills was originally [email-writer, writing-
    coach, interview-prep]; interview-prep is for job-interview
    preparation, not lead generation. Replaced with data-analyst
    (used by the qualification-scoring step in the prompt).

schema.toml: register mcp_servers / skills / max_history_messages on
the agent field schema so machine consumers (RegistrySchema in
librefang-types) see the new top-level fields. The
max_history_messages description now points at
librefang_runtime::agent_loop::DEFAULT_MAX_HISTORY_MESSAGES (60
today) by name, so the schema doesn't go stale when the constant
moves again.

agents/README.md: example block + "Adding a New Agent" checklist
mention the allowlists; max_history_messages example is shown
commented out with a prompt-cache caveat.

Open items
----------

`assistant` (the default user-facing agent) keeps `skills = []`
deliberately. It is the generalist entry point — capping its skill
surface at a small allowlist would defeat its "delegate to any
specialist" job. The trade-off is that this single agent still pays
the full skill-definition load on every turn; operators who want a
strict allowlist for `assistant` can override it after install.

Why not adopt PR #89's approach
-------------------------------

#89 covers similar ground but with three issues this PR avoids:

1. mcp_servers = ["_none"] sentinel. #89's body explicitly notes
   it's pending upstream librefang#4808 (mcp_disabled). Shipping a
   magic-string today means coming back later to clean it up. This
   PR uses real allowlists.
2. max_history_messages = 8 / 12 / 15 / 20. Far below today's
   kernel default (60) and #91's direction for long-workflow hands
   (80–120). Every turn that hits the cap invalidates the cached
   prompt prefix; the cost of cache misses exceeds the saving from
   shorter history. This PR uses 60–120.
3. Doubling max_llm_tokens_per_hour (coder 200k→500k, assistant
   300k→500k) widens the per-agent budget — the opposite direction
   from #87's "reduce per-call cost" goal. Left to the operator's
   instance-specific tuning.

Refs librefang/librefang-registry#87, librefang/librefang-registry#89
2026-05-12 09:30:21 +09:00
..

Agents Registry

Agent templates for LibreFang. Each entry is a ready-to-install agent definition with a pre-configured system prompt, model settings, capability declarations, and routing aliases.

These are the reference agents shipped with the registry. You can install them as-is, override individual fields (model, system_prompt, tools) after installation, or use them as base templates inside a Hand.

File Format

Each agent lives in its own subdirectory containing a single agent.toml:

agents/
├── coder/
│   └── agent.toml
├── orchestrator/
│   └── agent.toml
└── ...

agent.toml format

name = "coder"                       # must match directory name
version = "0.4.3-beta3-20260314"
description = "Expert software engineer. Reads, writes, and analyzes code."
author = "librefang"
module = "builtin:chat"              # runtime module — builtin:chat for all current agents

# Resource allowlists — keep these small. The kernel injects every entry's
# tools/skills into the agent's prompt on every LLM call, so an empty list
# (the default "all available" semantics) on an instance with many MCP
# servers and skills can burn 30-60k tokens per turn on definitions the
# agent never uses.
mcp_servers = ["memory", "git", "github", "filesystem"]   # [] = all available
skills = ["rust-expert", "python-expert", "git-expert"]   # [] = all available
# max_history_messages = 60          # OPT-IN override; omit to inherit kernel default
                                     # (default rises with the kernel; setting too low
                                     #  thrashes the prompt cache — measure before pinning)

[metadata.routing]
aliases = ["write code", "fix bug", "implement feature"]    # exact activation phrases
weak_aliases = ["refactor", "patch", "code change"]         # keyword hints

[model]
provider = "default"                 # default = use LibreFang's configured primary provider
model = "default"
api_key_env = "GEMINI_API_KEY"       # optional override: use this key env var
max_tokens = 8192
temperature = 0.3
system_prompt = """You are Coder, an expert software engineer..."""

[[fallback_models]]                  # optional: try these providers on failure
provider = "default"
model = "default"
api_key_env = "GROQ_API_KEY"

[schedule]                           # optional: continuous or cron activation
continuous = { check_interval_secs = 120 }

[resources]
max_llm_tokens_per_hour = 200000
max_concurrent_tools = 10

[capabilities]
tools = ["file_read", "file_write", "file_list", "shell_exec", "web_search", "web_fetch",
         "memory_store", "memory_recall"]
network = ["*"]                      # "*" = all, or list specific domains
memory_read = ["*"]
memory_write = ["self.*"]            # "self.*" = own namespace only
shell = ["cargo *", "rustc *", "git *", "npm *", "python *"]  # shell command allowlist
agent_spawn = false
agent_message = []                   # agents this agent may message

[i18n.zh]
name = "编码工程师"
description = "资深软件工程师:阅读、编写与分析代码。"

Installing and Using Agents

# List all available agent templates
librefang catalog agents

# Install an agent from the registry
librefang agent install coder

# Install with a custom name
librefang agent install coder --name my-coder

# List installed agents
librefang agent list

# Send a message to an installed agent
librefang agent message coder "Implement a binary search function in Rust"

# Remove an agent
librefang agent remove my-coder

Agents can also be used as base templates in a Hand by setting base = "coder" in HAND.toml.

All Agents (33 total)

Development

Name Description Key Tools
architect System architect. Designs software architectures, evaluates trade-offs, creates technical specifications. file_read, file_write, web_search, web_fetch
code-reviewer Senior code reviewer. Reviews PRs, identifies issues, suggests improvements with production standards. file_read, shell_exec, web_search
coder Expert software engineer. Reads, writes, and analyzes code. file_read, file_write, shell_exec, web_search
debugger Expert debugger. Traces bugs, analyzes stack traces, performs root cause analysis. file_read, shell_exec, web_search
devops-lead DevOps lead. Manages CI/CD, infrastructure, deployments, monitoring, and incident response. shell_exec, file_read, web_search
ops DevOps agent. Monitors systems, runs diagnostics, manages deployments. shell_exec, file_read, web_search
test-engineer Quality assurance engineer. Designs test strategies, writes tests, validates correctness. file_read, file_write, shell_exec

Research and Analysis

Name Description Key Tools
academic-researcher Academic research agent. Searches scholarly papers, summarizes findings, and generates literature reviews. web_search, web_fetch, file_write
analyst Data analyst. Processes data, generates insights, creates reports. file_read, web_search, web_fetch
data-scientist Data scientist. Analyzes datasets, builds models, creates visualizations, performs statistical analysis. file_read, file_write, shell_exec
researcher Research agent. Fetches web content and synthesizes information. web_search, web_fetch, memory_store

Writing and Documentation

Name Description Key Tools
doc-writer Technical writer. Creates documentation, README files, API docs, tutorials, and architecture guides. file_read, file_write, web_fetch
writer Content writer. Creates documentation, articles, and technical writing. file_read, file_write, web_search

Orchestration

Name Description Key Capabilities
orchestrator Meta-agent that decomposes complex tasks, delegates to specialist agents, and synthesizes results. agent_spawn, agent_send, agent_list, agent_kill
planner Project planner. Creates project plans, breaks down epics, estimates effort, identifies risks and dependencies. file_read, file_write, web_search

Business and Operations

Name Description Key Tools
customer-support Customer support agent for ticket handling, issue resolution, and customer communication. memory_store, memory_recall, web_search
email-assistant Email triage, drafting, scheduling, and inbox management agent. memory_store, memory_recall, file_write
legal-assistant Legal assistant agent for contract review, legal research, compliance checking, and document drafting. file_read, file_write, web_search
meeting-assistant Meeting notes, action items, agenda preparation, and follow-up tracking agent. memory_store, memory_recall, file_write
recruiter Recruiting agent for resume screening, candidate outreach, job description writing, and hiring pipeline management. web_search, file_read, memory_store
sales-assistant Sales assistant agent for CRM updates, outreach drafting, pipeline management, and deal tracking. memory_store, memory_recall, web_search
security-auditor Security specialist. Reviews code for vulnerabilities, checks configurations, performs threat modeling. file_read, shell_exec, web_search

Personal Productivity

Name Description Key Tools
assistant General-purpose assistant agent. The default agent for everyday tasks, questions, and conversations. file_read, file_write, web_search, memory_store
health-tracker Wellness tracking agent for health metrics, medication reminders, fitness goals, and lifestyle habits. memory_store, memory_recall, file_write
hello-world A friendly greeting agent that can read files, search the web, and answer everyday questions. file_read, web_search, web_fetch
home-automation Smart home control agent for IoT device management, automation rules, and home monitoring. shell_exec, memory_store, web_fetch
personal-finance Personal finance agent for budget tracking, expense analysis, savings goals, and financial planning. file_read, memory_store, web_search
recipe-assistant Cooking assistant that helps with recipes, meal plans, ingredient substitutions, and portion adjustments. web_search, memory_recall, file_write
social-media Social media content creation, scheduling, and engagement strategy agent. web_fetch, web_search, file_write
translator Multi-language translation agent for document translation, localization, and cross-cultural communication. file_read, file_write, web_fetch
travel-planner Trip planning agent for itinerary creation, booking research, budget estimation, and travel logistics. web_search, web_fetch, memory_store
tutor Teaching and explanation agent for learning, tutoring, and educational content creation. web_search, memory_recall, file_write

Capability Reference

Capability field Values Effect
tools list of tool names Which built-in tools the agent may invoke
network ["*"] or domain list Outbound HTTP domain allowlist
memory_read ["*"] or namespace list Which memory namespaces the agent can read
memory_write ["self.*"] or ["*"] Which memory namespaces the agent can write
shell glob patterns Shell command allowlist (e.g. "cargo *")
agent_spawn true / false Whether the agent can spawn child agents
agent_message ["*"] or agent name list Which agents this agent may send messages to

Adding a New Agent

  1. Create agents/<name>/agent.toml — name must match the directory name.
  2. Set module = "builtin:chat" unless you have a custom runtime module.
  3. Write a focused system_prompt — clear role definition, methodology, and constraints.
  4. Declare only the tools and capabilities the agent actually needs.
  5. Set mcp_servers and skills to the minimum the prompt actually references — leaving them empty falls back to "all available", which on a populated instance bloats every LLM call with tool definitions the agent never uses.
  6. Add [metadata.routing] aliases so the router can activate the agent by intent.
  7. Run python scripts/validate.py.
  8. Submit a PR.

See CONTRIBUTING.md for the full guide.