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

The phrase "Title discarded after the call" adds a concrete behavioral guarantee about data retention, and "Check whether...exists" implies a read-only existence test. With no annotations present, the description still does not state behavior on missing titles, network calls, or output semantics.

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?

Two short sentences, with the primary action front-loaded and the side-effect note in a second sentence. There is no redundant phrasing or filler.

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 simple checker with a required title and no output schema, the description gives the minimum needed to understand what the tool does. It leaves gaps: the result format is not stated, "exists" is not scoped to a Wikipedia language edition, and the many optional discarded params could confuse an agent deciding what to pass.

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?

Every schema property already has a description, so schema coverage is high and the description adds little new parameter meaning. The title parameter is already documented in the schema as "Wiki page title to check."

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 says "Check whether a Wikipedia title exists," which is a specific verb plus resource and makes the tool's core function clear. It does not explicitly distinguish this tool from siblings like citation or web-fetch, so it stops short of a 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?

There is no guidance about when to use this tool versus a citation, URL-shape, or title-search sibling. The required title parameter implies the obvious use case, but the description gives no explicit context or alternatives.

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