Agent Skills MCP

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, covering safety and idempotency. The description adds minimal behavioral context by specifying the search scope ('skill names and paths'), but does not detail aspects like rate limits, authentication needs, or pagination. With annotations providing core behavioral traits, the description adds some value but not rich additional disclosure.

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 a single, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded with the core action and target, making it easy to parse. Every part of the sentence contributes meaning, earning its place.

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 (search operation with multiple nested parameters), annotations cover key behavioral traits (read-only, idempotent, etc.), and an output schema exists (implied by context signals), the description is reasonably complete. It specifies the search scope but could improve by mentioning output handling or error conditions. However, with annotations and output schema, it meets most needs, though not fully exhaustive.

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 input schema has 100% description coverage for its single parameter 'params' (which nests query, repo, limit, response_format), with detailed field descriptions. The description adds no parameter-specific semantics beyond implying a general search query. Given high schema coverage, the baseline is 3, as the description doesn't enhance parameter understanding beyond what the schema already provides.

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 action ('Search') and target ('skill directories'), specifying that matching occurs against 'skill names and paths'. It distinguishes this from siblings like 'get_skill' (retrieve specific skill) and 'list_repositories' (list repos), though not explicitly. However, it doesn't fully differentiate from 'suggest_skill_scaffold' (which might involve search-like functionality), keeping it at 4 rather than 5.

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 usage for searching skill directories, but provides no explicit guidance on when to use this tool versus alternatives like 'get_skill' for retrieving a specific skill or 'suggest_skill_scaffold' for scaffolding suggestions. It lacks clear when/when-not instructions or named alternatives, relying on context from tool names only.

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