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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds 'No auth required' and licensing information (CC BY-SA 4.0 with attribution), which adds useful context beyond the annotations. It does not mention rate limits or edge cases, but the bar is lower given rich annotations, and this is sufficient.

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 concise and well-structured. It front-loads the main purpose, then lists return fields, language support, use case, auth, and licensing in a logical order. Every sentence adds value with no redundancy or fluff. It is appropriately sized for the tool's simplicity.

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 read-only tool with two parameters (one required) and an existing output schema, the description covers purpose, return fields, language support, use case, auth, and licensing. It provides everything an agent needs to decide when to call it and what to expect. No critical information is missing for correct invocation.

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?

Both parameters have detailed schema descriptions: title includes format and examples, language includes examples and default. Schema description coverage is 100%. The description mentions the optional language parameter for supporting 55+ language editions, but this adds little beyond the schema text. It meets the baseline of 3 for high coverage without significantly enhancing parameter understanding.

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 verb 'Fetch' and the resource 'introductory summary of any Wikipedia article', and lists the returned fields (plain-text extract, short description, thumbnail, Wikidata ID, canonical URL). It is specific and unambiguous. However, it does not differentiate from sibling tools like wikimedia-rest.pages.summary or wikipedia.article.media, so it lacks sibling differentiation which would earn 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?

The description gives usage context by stating it is 'Ideal for quick entity lookups: people, places, concepts, events, organizations', which implies when to use it. However, it does not mention any alternative tools or explicitly say when not to use it. There is no comparison with other Wikipedia or knowledge tools, so guidance is only implied, not explicit.

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