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

The phrase "Title discarded after the call" discloses one behavioral trait: no persistence of the title. But with no annotations present, the description carries the burden of explaining behavior, and it does not mention return values, error handling, network behavior, or whether this is a read-only operation. This is a minimal level of transparency, not a complete one.

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 very short: two sentences and no filler. It front-loads the core purpose and adds the discard note efficiently. It is appropriately sized for a simple check, though the brevity comes at the cost of essential invocation details.

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?

Given seven unrelated-looking parameters, no output schema, and no annotations, a 12-word description is far from complete. It does not identify which parameter is the title, what the response shape is, what 'exists' means in terms of output, or how failures are reported. An agent would not be able to invoke this tool confidently.

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 has seven parameters, each with a description, but none is clearly the Wikipedia title referenced by the tool. The description does not map 'title' to ref, url, city, feed, host, json, or path, so an agent cannot determine which parameter to supply. The schema descriptions are internally coherent but disconnected from the tool's stated purpose.

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 action and resource: "Check whether a Wikipedia title exists." This clearly distinguishes the tool from other shape-check siblings like browser-url-ok or github-repo-shape. However, it is slightly weakened by the input schema, which contains no obvious 'title' property and lists unrelated parameters like ref, url, city, and json.

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 gives no guidance about when to use this tool versus alternatives, nor does it mention exclusions or prerequisites. It does not say, for example, to prefer normalize-url for URL normalization or validate-json for JSON validation. Usage context must be entirely inferred from the name and the single sentence.

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