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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine value beyond them by stating the return shape ('titles, short descriptions and excerpts'), which matters because no output schema exists; it omits any note on rate limiting or result ordering.

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?

Two tight sentences: the operation first, the return value second. Nothing is wasted and nothing important is buried.

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?

The description compensates for the missing output schema by naming the returned fields, and the limit parameter's bounds are in the schema. The remaining gap is the lack of routing guidance relative to wikipedia_summary, which is the sibling an agent is most likely to confuse this with.

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 description coverage is 100% and both parameters are documented there, so the schema carries the load. The description adds no query syntax, matching behavior, or ranking detail beyond what the schema already says, matching the baseline 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?

States a specific verb and resource ('Full-text search of Wikipedia'), which is unambiguous and distinct from the other sibling tools. It stops short of explicitly naming wikipedia_summary as the alternative for a single-article lookup, so the sibling distinction is only implicit.

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?

Usage is only implied by the word 'search' – there is no statement of when to prefer this over wikipedia_summary, nor any prerequisite or exclusion. An agent can infer the split (query broadly vs. fetch a known article) but must do the inference itself.

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