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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses cost (0.005 credits per call) and an auth/rate-limit profile (works with no credentials up to 25 calls/day per address), which is genuinely useful operational context. It does not describe the return shape, but this exceeds what the annotations alone convey.

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?

A single tight parenthetical: resource first, then endpoint, cost, and auth constraints. No filler sentences and the substantive constraint information is front-loaded.

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?

For a read-only single-guru fetch with an enforcing annotation set and no output schema, the definition covers cost, auth, and scope adequately. The remaining gap is the undefined slug format, which an agent needs to invoke it successfully.

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 0% for the single `slug` parameter. The URL template embeds `{slug}`, implying it is a path identifier for the guru, but the description gives no format, source, or example of a valid slug value, so it only partially compensates.

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 states a specific resource and payload: "One guru: bio + top holdings." The singular "One guru" implicitly distinguishes it from the plural `gurus` list sibling, but it does not explicitly contrast with `guru_portfolio` or `guru_moves`, which also operate on a single guru.

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?

There is no when-to-use guidance or routing to alternatives. An agent must infer from the sibling names whether `guru_portfolio` or `guru_moves` is the better choice for deeper holdings or transaction history; the description offers no conditions.

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