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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds real value on top: it is cached and never generates, it exposes hasReport/scanStage state, and it prescribes the polling loop. It stops short of describing error behavior for invalid or unknown domains, so it is strong but not exhaustive.

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?

Front-loads identity ("The free public site report for any website") before the coverage list and the fallback procedure. The feature enumeration is dense but each item helps an agent decide whether this tool answers its question; minor trimming is possible.

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 no output schema, the description usefully tells the agent what comes back (the same data the public site-report page renders) and which state fields to inspect (hasReport, scanStage). For a single-parameter read tool this is nearly complete, lacking only failure-mode detail.

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?

There is only one parameter (domain) and schema description coverage is 100%, so the schema already carries the semantics. The description adds nothing about the domain format, normalization, or whether subdomains/paths are accepted, making the baseline 3 appropriate.

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?

Names a specific verb+resource (get the site report for a domain) and then enumerates exactly what sections it returns: performance, AEO, CRO, SEO crawl, CrUX, OpenPageRank, scorecards and named checks. It explicitly distinguishes itself from the sibling run_site_report by framing itself as the read of already-computed data.

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?

Gives explicit when-to-use and when-not-to-use guidance: this is the cached read that never generates, and if hasReport is false the agent should call run_site_report and then poll this tool until scanStage clears. That names the alternative and the exact condition that selects it.

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