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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: the result shape (source URLs and excerpts) and the explicit exclusion of validation/upload. It stops short of disclosing result ordering, rate limits, or what an empty result looks like.

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?

Three short sentences, zero filler. The core purpose and return format are front-loaded, and the exclusion clause follows as supporting scoping rather than as preamble.

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?

This is a simple two-parameter read tool with rich annotations, and the description covers purpose, return format, and scope, so it is broadly adequate. The notable gap is parameter guidance: with no output schema and 0% schema description coverage, the description is the only place query and limit semantics could appear, and they are absent.

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 0% – the schema exposes only constraints (query 2-160 chars, limit 1-10) with no semantics. The description never mentions 'query' or 'limit', so it fails to compensate for the coverage gap: an agent gets no hint about query syntax, matching behavior, or what the limit truncates.

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 ('Search XSDHub public XML and XSD guides') and immediately delimits scope by stating it does not validate or upload XML, which separates it from the validate_* siblings. It also says what comes back (source URLs and excerpts), so an agent knows this is a discovery tool, not a fetch or validation tool.

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 negative guidance ('Does not validate or upload XML') implies the correct routing toward the validate_* tools and hints at a search-then-fetch flow with get_xsdhub_page, but no alternative is named and no when-to-use condition is stated explicitly. An agent can infer usage but must do the work itself.

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