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

Beyond the readOnlyHint annotation, the description reveals critical behaviors: privacy-preserving identical not_found responses, the manifest structure (parts, clips subset, stats null semantics), the exact response shape ({ ok, manifest } vs. bare manifest via HTTP), and required scope. This is rich, non-obvious behavioral context that fully informs the agent.

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 but information-dense paragraph covering privacy, manifest shape, alternative access, response format, and scope. Every sentence contributes value, though the density could be improved with bullet points for scannability. It is not wasteful, but slightly beyond minimal.

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 no output schema, the description shoulders the burden of explaining the response, which it does thoroughly: { ok, manifest } or { ok:false, error_kind:'not_found' } plus details about manifest fields. It also includes privacy semantics, the HTTP alternative, and required scope, making it fully complete for a single-parameter tool.

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 already fully documents the handle parameter (type, length, description, example, case-insensitivity), and the description adds no new parameter semantics beyond repeating 'Args: { handle: string }'. Since schema coverage is 100%, a baseline score of 3 is appropriate; the description adds no meaningful parameter insight.

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 a specific verb ('Fetch') and resource ('a member's published vinyl-figure manifest by handle'), and distinguishes itself from sibling tool ic_funko_get_mine by noting it retrieves 'another member's' figure while citing the same manifest shape. It establishes exactly what the tool does and what it returns.

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 explicitly warns that only published figures are accessible and that unopted members return the same not_found as nonexistent handles, providing a clear when-to-use context. It also names an alternative (the direct HTTP endpoint) and implicitly distinguishes from the self-service ic_funko_get_mine tool, offering excellent guidance on when to use this tool vs. alternatives.

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