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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so safety is covered. The description adds the return shape ({ package, current_version, releases: [...] }), the default of the last 3 releases, and that sections are omitted when filtered — useful context beyond the annotations, though the default cap is also repeated from the schema.

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?

Front-loaded with the use case, then the return shape, then filtering, then the next step — a clean progression. Slightly dense with the quoted trigger-phrase list and the inline JSON return signature, but every element serves selection or invocation.

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?

No output schema exists, yet the description spells out the return object and the default release count, and it covers filtering behavior and a follow-up tool. Nothing an agent needs in order to call this correctly is missing.

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 limit, sections, and since_version are already fully documented in the schema, including defaults, max, and semver-comparison behavior. The description only restates that since_version bounds output and sections filter Added/Fixed/etc., adding no new semantics.

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?

States a specific verb and resource ('Returns recent releases of the PICA directory MCP server') and immediately scopes it to the public catalogue surface itself, not catalogue content. The explicit 'NOT for catalogue content searches (use directory_search / directory_list_works / directory_chain)' separates it from siblings without requiring schema inspection.

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?

Gives literal trigger phrasings, an explicit exclusion with the three sibling tools that handle the excluded case, and a follow-up route ('then: directory_search'). When-to-use, when-not-to-use, and alternatives are all present.

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