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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only notes that the title is discarded after the call, but does not state whether it performs a network request, whether it is read-only, what it returns (e.g., boolean), or any side effects. This is minimal and insufficient.

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 a single sentence with no fluff, and it front-loads the core purpose. It is concise and easy to parse. However, it omits essential information that a longer description could have included, so it earns a 4 rather than a 5.

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 tool with 9 parameters, no annotations, and no output schema, the description is severely incomplete. It does not explain how to invoke the tool (which parameter holds the title), what the expected output is, or any constraints (e.g., network dependency). The description leaves too much to inference, making it inadequate for an agent to call correctly.

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 does not clarify which parameter corresponds to the Wikipedia title, despite the schema having 9 optional parameters with vague descriptions like 'Git ref name; discarded after the shape check' and 'Search text; discarded after the length check'. Although schema coverage is 100%, the parameter descriptions are unrelated to the tool's stated purpose, and the description adds no meaning to bridge the gap.

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 clear verb and resource: 'Check whether a Wikipedia title exists.' This is specific and distinguishes the tool from siblings like 'browser-url-ok' or 'normalize-url'. However, the schema lacks a parameter for the title, which could confuse an agent about how to provide it, so it's not a perfect 5.

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?

No guidance on when to use this tool versus alternatives. It does not mention scenarios, exclusions, or sibling tools. The description is a single statement of purpose with no usage context.

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