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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, establishing a safe, read-only operation. The description adds valuable beyond-annotation context: 'No auth required' clarifies access, 'Up to 50 results per query' sets a limit, 'Supports 55+ language editions' indicates multilingual capability, and the licensing statement provides usage terms. These enrich the behavioral profile without contradicting the annotations.

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 a single, well-structured sentence followed by two short supporting sentences. It fronts the primary purpose with specific return fields, then packs in language support, result limits, auth, and licensing without waste. Every sentence earns its place, making it an efficient and scannable definition.

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 the presence of a rich output schema (not shown but noted as present), the description correctly avoids detailing return value structure. It includes operational limits (max results, language editions), auth requirements, and licensing. However, it stops short of mentioning pagination, error handling, or how it relates to sibling search tools, which would further aid agent decision-making. Slight gap for a search tool, but acceptable given the annotations.

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?

Schema coverage is 100% with each parameter (query, limit, language) already given descriptive comments. The tool description adds no extra meaning to these parameters: it does not elaborate on query syntax, default behavior, or language codes beyond what the schema provides. Since the schema carries the load, the description adds minimal incremental value, aligning with the baseline of 3.

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 tool's function: 'Search Wikipedia for articles matching a keyword or phrase' and specifies the return fields (titles, Wikidata descriptions, excerpts, thumbnails). This verb+resource phrasing is specific and distinguishes it from other Wikipedia tools like article.summary or media retrieval. It also highlights language editions and result limits, reinforcing its purpose.

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 usage for keyword-based Wikipedia article discovery, but it does not explicitly reference alternative tools or advise when NOT to use this tool. For example, it doesn't mention that for a specific article summary, wikimedia-rest.pages.summary might be more appropriate. The purpose is clear, but no exclusions or comparisons are provided, leaving the agent to infer context.

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