Code Whisperer MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly describes what the tool does (lists skills with specific fields) and mentions the relationship with get_skill. However, it doesn't address important behavioral aspects like whether this requires authentication (though the schema shows an optional api_key parameter), rate limits, pagination, or error conditions. The description adds value but leaves gaps in behavioral transparency.

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?

The description is perfectly concise with two sentences that each serve distinct purposes: the first explains what the tool does and what information it returns, the second provides explicit usage guidance by contrasting with a sibling tool. There is zero wasted text, and the information is front-loaded with the core functionality.

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?

Given the tool's moderate complexity (listing operation with one optional parameter), no annotations, and no output schema, the description does a good job of explaining the tool's purpose, output format, and relationship to other tools. However, it doesn't address authentication requirements (implied by the api_key parameter but not explained), error handling, or what happens when no skills are available. For a tool with no annotations or output schema, it's mostly complete but has minor gaps.

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?

The schema description coverage is 100% with one parameter (api_key) documented in the schema. The description doesn't mention parameters at all, which is appropriate since the schema fully documents the single optional parameter. With zero parameters mentioned in the description and high schema coverage, the baseline would be 3, but the description effectively focuses on the tool's purpose rather than repeating schema information, earning a slightly higher score.

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 clearly states the specific action ('List all available Claude Code skills') and the resource ('skills'), including what information is returned ('slug, title, category, and description'). It also distinguishes from the sibling 'get_skill' by mentioning that tool fetches full content for a specific skill, while this one lists all skills with summary information.

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 provides explicit guidance on when to use this tool versus alternatives: 'Use list_skills to see all available skills with summary information' (implied) and 'Use get_skill to fetch the full SKILL.md content for a specific skill.' This clearly differentiates between browsing all skills and getting detailed content for one skill.

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