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

Annotations already cover read-only/idempotent/closed-world, and the description goes well beyond them: it discloses conditional content ('verbatim source passage (when licensing allows)') and an explicit CC BY 4.0 attribution obligation with the exact required string. That licensing obligation is a real behavioral constraint an agent must honor that no annotation conveys.

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 front-loaded sentence that identifies the resource first, then the returned fields, then the licensing terms. Dense but nearly every clause carries information; only the full enumeration of citation formats is mildly padded given an output schema exists.

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?

An output schema exists, so listing return fields is largely redundant, but the description adds value the schema cannot: the conditional verbatim passage and the mandatory attribution text. What remains missing is discovery guidance (how to get a valid slug), which is the main completeness gap.

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, so the description carries the burden; it only says 'by slug' without defining slug format, accepted patterns, or error behavior for an unknown slug. The schema's two examples partially compensate, keeping this at minimum-viable rather than failing.

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: retrieves one Whirrwork Research statistic by slug, and enumerates the payload the caller gets back. It is clearly distinguishable from search_stats by the singular 'one ... by slug' framing, though it never names the sibling that finds slugs.

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 never says when to use this tool versus search_stats, get_use_case, or any other sibling, nor does it state the precondition that a slug must already be known and where to obtain one. Only the phrase 'by slug' hints at usage context.

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