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

Goes well beyond the annotations by describing the check mechanism ('loads the site the way a visitor's browser does'), the latency ('takes up to about a minute'), the failure mode (no quality score when unreachable or blocking), and a rate limit ('free checks are limited per person and per website each day'). It also enumerates the six audited areas and clarifies that problems are counted but not named, which an agent cannot infer from readOnlyHint/idempotentHint alone.

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?

Well front-loaded: what it does, what it returns, and when to use it all appear in the first few sentences. It is somewhat longer than necessary, and the sentence 'It only finds problems; it never changes anything on the site' largely restates the readOnlyHint/destructiveHint annotations rather than adding new information.

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?

For a one-parameter, no-output-schema tool, the description covers everything an agent needs: purpose, return contents, the six audited areas, latency expectations, failure behavior, and daily per-person/per-site limits. Nothing material about invoking it correctly is left undocumented.

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 exists and schema_description_coverage is 100%, with the schema already supplying format and examples ('https://yoursite.com or yoursite.com'). The description adds only a mild constraint by calling it a 'public' website, which implies the URL must be publicly reachable, but it gives no further syntax or normalization guidance. Baseline 3 is appropriate when the schema does the heavy lifting.

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 opening sentence names a specific verb and resource ('Checks a public website with Sitecomb') and immediately describes the return shape: a quality score out of 100 plus problem areas with counts. It also distinguishes itself from a fuller report ('It does not name the problems: those are in the full report'), though it never names the sibling tool explain_area, so differentiation is implied rather than explicit.

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?

Offers multiple concrete triggering situations: whether a site is 'any good', 'what is wrong with it', 'why their website isn't working for them', or a request to 'check or audit a website'. It also states a failure condition (site down or blocking automated checks yields no score). What is missing is an explicit exclusion or named alternative for the case where the user needs the actual problem names, which is only hinted at via 'those are in the full report'.

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