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

No annotations are provided, so the description carries the full behavioral burden. The only behavioral note ('Title discarded after the call') is contradicted by the schema's own disposal semantics ('discarded after the shape check', 'no disk access', 'discarded after the length check'), which describe a generic input validator rather than a Wikipedia title check. The behavior described does not match the tool.

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 (two clauses), which is structurally concise, but the brevity serves misleading content. Conciseness only earns credit when the content is accurate; here it packages a false purpose into a compact statement.

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 9-parameter tool with no output schema and no annotations, the description should at least clarify the tool's purpose and which inputs it expects. Instead it describes a completely different function. Nothing an agent needs to call this tool correctly is present; the description is not just incomplete but actively wrong.

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?

Although schema coverage is 100%, the description's stated purpose maps to zero of the 9 parameters. There is no 'title' parameter, so an agent cannot determine which field holds the Wikipedia title the description asks it to check. The description adds no clarifying meaning to any parameter and in fact conflicts with all of them.

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+resource ('Check whether a Wikipedia title exists'), but it is misleading: none of the 9 schema parameters (ref, url, city, feed, host, json, path, zone, query) represents a Wikipedia title. An agent following this description would look for a title parameter that does not exist, so the stated purpose is disconnected from the tool's actual input surface.

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 when-to-use guidance and no reference to any of the 28 sibling tools. Worse, the implied usage (Wikipedia title lookup) contradicts the actual parameters (URL, ref, JSON, timezone, etc.), which resemble the shape-checking siblings like file-path-ok and validate-json. The description would actively misroute an agent to the wrong inputs.

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