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

With no annotations present, the description carries the behavioral disclosure burden. It does disclose one useful trait: 'Title discarded after the call,' indicating the input is not persisted. It does not mention return format, network behavior, or limitations, so transparency is only partial.

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 no filler. The key action is front-loaded, and the additional discard behavior earns its place, so this is 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 simple existence-check tool, the description states the purpose and side effect, but no output schema or annotations exist and the parameter mismatch is unresolved. The agent is missing essential information about what input represents the title and what the tool returns.

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 adds no mapping from 'Wikipedia title' to any schema property. The schema lists seven generic parameters (ref, url, city, feed, host, json, path) with unrelated descriptions, and none clearly represents a Wikipedia title. An agent cannot determine how to invoke this tool correctly.

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 is specific: 'Check whether a Wikipedia title exists' names a clear verb and resource, distinguishing it from sibling shape-check tools like domain-shape or file-path-ok. However, it does not indicate which input parameter carries the Wikipedia title, so the purpose is not fully actionable.

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 description implies when to use the tool: whenever an agent needs to verify that a Wikipedia title exists. It does not explicitly name alternatives or exclusions, but the use case is reasonably inferred from the sentence.

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