Inventory installed skills

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description redundantly restates 'Read-only' but adds useful context about what the tool reports (duplicate names, read errors). It doesn't contradict annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two concise sentences that efficiently convey the tool's purpose and outputs. The 'Read-only' clarifying note is slightly redundant given the annotations but harmless. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter, read-only, idempotent tool with a fully-covered schema, the description covers the essential behavior adequately. It describes what gets indexed and what summaries are produced. Could mention the format of the summary output, but given zero params required and no nested objects, this is complete enough for an agent to use confidently.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the single parameter (includeDuplicatePaths) is fully documented in the schema itself. The description mentions 'duplicate names' as an output, which loosely relates to the parameter, but the schema already explains it clearly. Baseline 3 is appropriate when the schema handles parameter documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb ('Index') with a clear resource ('installed SKILL.md files') and enumerates the specific outputs (roots, invocation modes, duplicate names, read errors). This distinguishes it well from sibling tools like search_skills and recommend_skills, though it doesn't explicitly name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies this is an administrative/inspection tool and states it is 'Read-only,' but it doesn't explicitly say when to use it over alternatives like search_skills or explain_skill. The context is clear enough for an agent to infer it's for inventorying installed skills vs searching/recommending, but no explicit exclusions are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.