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skill invocation

MCP Tools

Choose the best OpenClaw skill by matching trigger keywords to the TOOLS.md index, then applying strict judgment rules (most specific first; if in doubt, use it).

Install

openclaw skills install skill-invocation

Skill Invocation System

This is a framework-style skill for "skill selection and invocation flow". It does not implement a specific tool; instead, it provides stable decision rules for an agent to choose the best skill (or skill combination) for a user request.

Core Principles

  1. Match the index first: consult TOOLS.md (skills index) to quickly narrow down candidate skills.
  2. Most specific wins: when multiple candidates match, choose the one whose triggers best align with the user's intent.
  3. When unsure, consult SKILL.md: if still unclear, read the candidate skill's SKILL.md to confirm fit and constraints.
  4. If in doubt, use it: if you cannot decide, pick the closest and usable candidate skill.

Invocation Flow

When a user request arrives, follow this order:

  1. Match trigger keywords using the TOOLS.md index.
  2. If matched with high confidence → use that skill.
  3. If no match / unclear → read the candidate skill's SKILL.md.
  4. If multiple are suitable → choose the most specific one.
  5. If still unclear → use "if in doubt, use it".

Requirements: Provide TOOLS.md

To make this skill reusable by anyone, your workspace needs a TOOLS.md (or an equivalent index) that maps "user intent / trigger keywords" to "candidate skill ids".

Index Contract

In TOOLS.md, skillId should follow one of these rules (pick one and keep it consistent):

  1. Equal to the skill folder name (for example: ~/.openclaw/workspace/skills/<skillId>/SKILL.md)
  2. Or equal to the name/slug your orchestration layer uses to call that skill

As long as skillId matches the actual callable skill identifier, this framework can be reused by anyone.

Suggested TOOLS.md format (minimum viable):

# TOOLS.md

## Skills Index
| skillId | triggers | summary |
|---|---|---|
| weather | current weather, forecast | Get weather & forecast |
| summarize | summarize, tl;dr | Summarize URLs/files/PDFs |
| stock-info-explorer | stock, quote, ticker | Analyze stock price & basics |

Matching rules (agent-side):

  1. Split triggers by commas / delimiters into multiple trigger phrases.
  2. Do case-insensitive matching against the user message; if a trigger phrase "appears", count it as a hit.
  3. When multiple candidates match, use a "most specific first" heuristic:
    • Longer trigger phrases are more specific (for example: current weather is more specific than weather)
    • More matched trigger keywords is more specific
    • Higher semantic alignment with the candidate's summary (closer wording) is more specific

When the index matches but you are still uncertain:

  1. Read the candidate skill's SKILL.md.
  2. Look for sections like When to Use, Decision Rules, or "Notes/Constraints" to validate fit.
  3. If you cannot find enough evidence or there is an obvious mismatch, fall back to "if in doubt, use it".

Decision Output (recommended output contract)

To make orchestration easier, when making a decision this skill should output (order does not matter):

  1. SELECTED_SKILLS: the list of selected skillIds (one or many)
  2. REASON: a short explanation of which triggers matched and why the choice is most specific
  3. NEXT_ACTION: the recommended calling plan for the orchestrator (for example: call the first skill, then the second)

Optional: Combination Strategy (optional)

If you want a single request to map to multiple steps, you can define an additional "combination" section in TOOLS.md (not required). When the agent detects that triggers hit multiple steps:

  1. Execute the most core step first (often "input / retrieval / preparation").
  2. Execute the step closest to the desired output shape next (for example: summarizing / formatting / exporting).

(The exact definition format is up to you; the key is that TOOLS.md explains why the combination is needed.)

Judgment Checklist (when unsure)

If you cannot decide which skill to use, check in order:

  1. Is the request covered by the candidate skill's description? → Yes → use it
  2. Could the request be handled better without this skill? → No → use it
  3. Still cannot decide → "if in doubt, use it"

Index Maintenance (optional)

If you maintain the TOOLS.md index, keep it accurate so selection logic stays reliable:

  1. Scan your workspace/install directories for candidate skill folders (according to your OpenClaw installation conventions).
  2. For each skill, read its SKILL.md for "when to use / trigger suggestions / constraints" (if available).
  3. Add or update each skill's skillId + triggers + summary in TOOLS.md.
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