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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description goes beyond them by disclosing the result shape (each detected type with its errors and warnings for rich results) and that both JSON-LD and Microdata are scanned, which is genuinely useful. It stops short of noting rate limits, auth needs, or how an unreachable/unsupported URL is handled.

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?

One tightly structured sentence, front-loaded with the verb and resource, then a colon-delimited elaboration on the return content. No filler or restatement of the title.

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?

With only one parameter and no output schema, the description does the necessary work by summarizing what comes back (per-type errors and warnings for rich results). That is adequate for a read-only validator, though a touch more on return granularity or failure modes would make it fully self-sufficient.

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% for the single url parameter, so the schema already carries the semantics and the baseline is 3. The description adds no format guidance (absolute vs relative URL, public accessibility) beyond what the schema states.

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 pair (find and validate) against a named resource (Schema.org structured data, explicitly JSON-LD and Microdata) scoped to a URL. That scope cleanly separates it from siblings like check_meta_tags and validate_sitemap, which an agent can distinguish without opening any schema.

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 resource: an agent can infer it should call this when it wants to check structured data on a page. No explicit when-to-use condition, prerequisite, or alternative (e.g. check_meta_tags for meta tags) is named, so the routing guidance is thin.

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