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

Annotations already declare readOnly, idempotent and openWorld, so the description is not carrying the safety burden; instead it adds genuine value by disclosing the scoring formula (mean of crawler, schema and answer-readiness) and explaining why llms.txt is reported but excluded. Cost/auth ('free, no key') and a docs link are also given, though rate limits and failure behavior are not.

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, front-loaded with what runs and what is returned; the scoring rule and the llms.txt exclusion each earn their place because they change how an agent interprets the output. The docs URL is placed last where it belongs.

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?

There is no output schema, so the description must stand in for return-value semantics; it does so at a coarse level (four check results plus an overall score, with the scoring basis stated). It stops short of describing per-check result shape or error responses for unreachable URLs, which is the remaining gap.

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?

Only one parameter and the schema documents it fully at 100% coverage, including the https:// normalization behavior, so the baseline is 3. The description's phrase 'one address' reinforces the single-URL scope but adds no format or edge-case detail beyond the schema.

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 ('Runs all four checks on one address') and enumerates the four checks, which map directly onto the sibling tools (crawler access, structured data, llms.txt, answer readiness). An agent can immediately tell this is the aggregate/superset tool versus the single-check siblings.

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 context is clear: one address, all four checks, free with no key. Naming the four checks implicitly frames the alternative (call the individual sibling tools for a single check), but it never states when to prefer the granular tools or what to do with a multi-page site.

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