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

With no annotations, the description carries the full burden. It adds a small behavioral detail ('Title discarded after the call') but does not disclose whether the tool makes a network request, how it determines existence, possible side effects, or failure modes. The schema's repeated 'discarded' notes are not sufficient to explain behavior.

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, which is good, but it omits essential context. The single extra sentence about discarding the title is not useful without a corresponding parameter, and the description does not earn its place by clarifying invocation. It is under-specified rather than appropriately concise.

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 a declared purpose of checking Wikipedia title existence, the absence of a title parameter and any explanation of how to call it makes the definition fundamentally incomplete. The schema is a grab-bag of unrelated fields, and there is no output schema or usage context. An agent would likely fail to invoke this tool 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 provides no explanation of parameters, and the schema's parameters (ref, url, city, feed, host, json, path) are unrelated to a Wikipedia title. There is no 'title' field, and the schema descriptions do not bridge the gap. An agent cannot determine which parameter, if any, should contain the Wikipedia title, making the parameter semantics actively misleading.

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 tool's action and resource: 'Check whether a Wikipedia title exists.' This is a specific verb+resource combination and is distinguishable from sibling tools by its focus on Wikipedia title existence. However, the description does not mention how this relates to the listed parameters, which slightly weakens clarity.

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 alternatives, no prerequisites, and no exclusion criteria. The description simply states what it does without contextualizing the choice among the many '-shape' and '-ok' sibling tools.

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