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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the 'public' scope constraint, which is genuinely useful context not in the annotations. However, the field list (image, board, pinner, comments/saves, creation time) largely duplicates what the output schema already provides, so added behavioral value is modest.

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 sentences with zero waste; the core purpose is front-loaded and the routing advice follows immediately. Every clause earns 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?

With an output schema covering return fields and annotations covering the safety profile, the description only needs to state purpose and routing, which it does fully. Nothing an agent needs 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% and the single `id` parameter is already documented as 'Pinterest pin id'. The description's 'by `id`' phrasing adds no syntax, format, or source guidance beyond the schema, so the baseline 3 applies.

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 ('Fetch one public Pinterest pin's full details by `id`') and enumerates the returned content (image, board, pinner, comments/saves, creation time). It clearly distinguishes itself from the discovery siblings it names, so an agent can tell it apart without opening any schema.

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?

Explicitly routes the agent: use this to fetch a specific pin, and use pinterest_user_pins, pinterest_board, pinterest_idea, or pinterest_search to discover pins. The when-to-use and the alternatives are both stated, leaving nothing to inference.

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