tool-defs-analysis

tool-defs-analysis is a skill for Claude Code from cyanheads/obsidian-mcp-server. It costs 177 tokens per session (4,277 once invoked), scanned A, original, Apache-2.0.

A read-only review of the language used in tools, data sources, prompts, and server instructions that a coding agent can see.

In plain words
What is it for?
It audits 16 categories of definition text, including voice, hidden implementation details, defaults, audience assumptions, parameter descriptions, and recovery guidance.
Why use it?
It checks whether those definitions are clear enough for the agent to choose tools, fill in fields, and recover from errors without internal or confusing wording.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the obsidian-mcp-server plugin — 33 skills, 1 MCP server shipped together

Good fit It audits 16 categories of definition text, including voice, hidden implementation details, defaults, audience assumptions, parameter descriptions, and recovery guidance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cyanheads/obsidian-mcp-server/tool-defs-analysis
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add cyanheads/obsidian-mcp-server --skill tool-defs-analysis
Clone the repo
git clone --depth 1 https://github.com/cyanheads/obsidian-mcp-server

Made for: Claude Code.

Or install obsidian-mcp-server, the plugin that ships this one along with the rest of its 33 skills, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for tool-defs-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis/github.svg)](https://agentmods.dev/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis)
Your own site
<a href="https://agentmods.dev/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis"><img src="https://agentmods.dev/badge/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for tool-defs-analysis

Your own site · 80×15
<a href="https://agentmods.dev/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis"><img src="https://agentmods.dev/badge/skills/cyanheads/obsidian-mcp-server/tool-defs-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 177 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,277 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Memory Poisoning · line 249
    Skill attempts to fill the context window with filler content, displacing legitimate instructions and safety constraints. This can degrade agent performance or bypass safety boundaries.
    Fix: Implement context-window management that detects and rejects padding or stuffing attempts. Prioritize system instructions over user-injected content.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00177 $0.04277
Opus 5 $0.00088 $0.02139
Sonnet 5 $0.00035 $0.00855
Haiku 4.5 $0.00018 $0.00428

Measured 10d ago against content hash 1d1f27b114eb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

tool-defs-analysis scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

8 near-identical copies found in the catalogue:

skills/tool-defs-analysis/SKILL.md · 280 lines

How it starts

The opening of the file, as written. The whole thing — 280 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Context

Every string in a tool/resource/prompt definition is part of an LLM-facing API contract. The model reads the description, every parameter .describe(), the output schema, the recovery hints — and decides what to call and how. Definition language drifts: an internal mapping leaks into a parameter doc during a fix, a self-referential output description survives a refactor, a default that suited the developer at scaffold time stays after the typical call shape changes.

This skill is the review-time pass for that drift. Read each definition the way a mid-tier model with no project context would — can it pick the tool, fill the fields, and recover from errors using only the rendered schema?

Skill Lens
design-mcp-server Authoring rules at write-time
field-test Behavior testing + a narrow 3-category leak audit
security-pass Injection, scopes, input sinks
tool-defs-analysis (this) LLM-facing language across the existing surface

field-test already audits descriptions for implementation leaks, meta-coaching, and consumer-aware phrasing during its catalog step — that's a fast shallow pass alongside live tool calls. This skill is the deeper review: 16 categories, every field, every recovery hint, every default value, with file:line citations — plus a cross-surface pass for the drift no single file shows.

Read-only. This skill produces a report; the maintainer applies fixes. While running it, do not run git, do not stage or commit, do not update the changelog, do not run devcheck, do not invoke wrapup or release workflows. Fixes flow through the normal authoring path (edit the definition, then re-run this skill if you want to verify).

When to Use

  • After a polish session or refactor that touched definitions
  • Before a release, alongside polish-docs-meta and security-pass
  • When the user says "review my tool definitions", "audit descriptions", "are my tool descriptions any good"
  • After scaffolding a new server but before it ships

Read the full file on GitHub · 280 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 280 lines · 177 tokens per session scan A 1d1f27b114eb

Subscribe to this mod's changes

tool-defs-analysis is a skill published in the GitHub repository cyanheads/obsidian-mcp-server (676 stars, last pushed today), licensed Apache-2.0. It adds 177 tokens to every session and 4,277 once invoked, about $0.0009 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

knowledge-base-management

A lifecycle system for managing an Obsidian knowledge base, which is a folder of linked notes. It organizes raw material, AI-maintained wiki pages, and generated views into separate layers.

chubbyguan/chubbyskills · 49 tokens

pkm-session-end

Use when wrapping up a work session — creates devlog entry, captures undocumented decisions/research/debugging, audits link health of session work, and updates project index. Primarily used via the pkm-capture agent.

AdrianV101/obsidian-pkm-plugin · 49 tokens

pkm-write

Use when writing to the vault — creating new notes (vaultwrite), editing existing notes (vaultedit, vaultappend, vaultupdatefrontmatter). Handles duplicate checking, link discovery, annotations, and index updates for new notes. Provides guidelines for modifications.

AdrianV101/obsidian-pkm-plugin · 54 tokens

triage-tasks

Use when you want to review and batch-update open vault task statuses for the current project or across all projects.

AdrianV101/obsidian-pkm-plugin · 27 tokens

pkm-explore

Use when researching what the vault knows about a topic — performs graph + semantic exploration with gap analysis to map existing knowledge and find missing connections. Primarily used via the vault-explorer agent. Not for routine session-start context loading (hooks handle that).

AdrianV101/obsidian-pkm-plugin · 55 tokens

tackle-task

Use when starting work on a specific vault task, when a task title or path is mentioned, or when coming from triage output.

AdrianV101/obsidian-pkm-plugin · 31 tokens