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

With no annotations to rely on, the description carries the behavioral burden, but it only adds 'Title discarded after the call.' It does not disclose network behavior, return format, failure semantics, rate limits, or what 'exists' means.

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 two short sentences with the core action front-loaded and no filler. It loses points only because the brevity hides essential parameter mapping information.

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?

Given eight unrelated input parameters, no annotations, and no output schema, the definition is far from complete. The missing mapping from 'title' to an actual input parameter makes the tool effectively uncallable from the description alone.

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 centers on a 'title,' yet the input schema contains no title property; the eight properties (ref, url, city, feed, host, json, path) are not mapped to the title input. An agent cannot determine which parameter to populate, despite the schema giving each property its own description.

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 opening sentence uses a specific verb and resource: 'Check whether a Wikipedia title exists.' It is not a tautology and is distinct from sibling shape/hint tools. However, the missing title parameter slightly blurs how the purpose maps to an invocation.

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?

The use case is implied: an agent should call this when it needs to know whether a Wikipedia title exists. There is no explicit guidance about when not to use it, prerequisites, or alternatives among the sibling tools.

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