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

With no annotations present, the description carries the full burden of behavioral disclosure. It usefully notes that the title is discarded after the call, but it does not disclose the output format, error behavior, network effects, or explicitly confirm that the operation is strictly read-only beyond the implicature of 'check'. This is insufficient without annotation support.

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 two short sentences with no filler: the first states the purpose, and the second adds a relevant data-handling side effect. It is front-loaded and concise, even though its brevity contributes to completeness gaps penalized elsewhere.

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?

The tool has seven input parameters, no annotations, and no output schema, so the description must explain how to invoke it and what to expect. It does neither: the 'title' concept from the description has no matching parameter, and the schema's parameter descriptions look unrelated to Wikipedia title checking, leaving the tool effectively non-invocable.

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 description refers to a 'Wikipedia title', but the input schema contains no 'title' parameter; instead it lists ref, url, city, feed, host, json, and path with descriptions that appear unrelated. The description gives the agent no way to determine which parameter carries the title, making correct invocation impossible as described.

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 the action ('Check whether a Wikipedia title exists') and the resource (Wikipedia title), making the tool's purpose immediately understandable and distinct from sibling tools that check URLs, robots, or JSON. However, it does not explicitly differentiate from related tools or describe the return value.

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 a clear context for use: when an agent needs to verify whether a Wikipedia title exists. It does not include explicit exclusions or mention named alternatives, such as normalize-url or web-fetch, so it stops short of a full 5.

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