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

With no annotations, the description must carry the full behavioral disclosure burden. It provides one meaningful behavioral clue ('Title discarded after the call'), but does not explain what happens during the check, whether a network request occurs, what is returned, or what errors/side effects may occur.

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 and front-loaded with the action. The second clause about discarding the title also adds behavioral value. It earns a 4 rather than 5 because the brevity is not well matched to a nine-parameter tool that needs more orientation.

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?

This is not complete enough for an agent to call the tool correctly: there is no output schema defining the return value, no mapping from title to an input parameter, no explanation of optional parameter behavior, and no mention of error cases. For a simple check with nine unrelated optional parameters, more context is required.

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 100% description coverage, but all nine parameters are described generically and none is named as the Wikipedia title. The description never maps 'title' to any parameter, so an agent cannot know whether to pass it as query, url, ref, or something else. Schema coverage does not compensate because the schema itself fails to support the 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 verb and resource: 'Check whether a Wikipedia title exists.' This makes the core purpose clear and separates it from sibling tools that check URLs, files, or statuses. It loses a point because the description never indicates which of the nine schema parameters actually supplies the title.

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?

There is no guidance on when to use this tool versus siblings such as web-fetch, browser-url-ok, or search-query-len, and no mention of when not to use it. The purpose is implied, but context for selection among alternatives is completely absent.

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