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

No annotations are provided, so the description must carry the burden. It does disclose that the title is discarded after the call, implying no retention. However, it does not reveal network behavior, error handling, return values, or whether the check is local or remote.

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 short, front-loaded, and free of filler. The second sentence adds one useful behavioral detail. It is not a 5 because the brevity leaves critical invocation information unstated.

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 nine optional parameters, no annotations, and no output schema, the description is severely incomplete. The schema provides per-parameter descriptions, but they do not align with the advertised Wikipedia-title check, so the agent still cannot confidently select inputs or understand expected behavior.

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?

Even though schema coverage is 100%, none of the nine parameters is described as the Wikipedia title. The closest candidate, 'query', is documented as 'Search text; discarded after the length check,' which does not match the advertised purpose. The description mentions 'Title' but never maps it to a schema property, making invocation unreliable.

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 gives a specific verb and resource: 'Check whether a Wikipedia title exists.' This clearly identifies the tool's core operation. It is less than a 5 because it does not explicitly differentiate itself from related siblings like citation or normalize-url.

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 provides no guidance on when to use this tool versus alternatives. With 27 sibling tools, there is no mention of conditions, exclusions, or a preferred alternative.

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