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

Annotations already state readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable behavioral context beyond that: it takes 5–40 seconds, is read-only with 'nothing on the scanned site is changed,' and the agent-readiness score never affects the main score. No contradiction with annotations.

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?

The description is well-structured and information-dense: it front-loads the report contents, then gives use cases, scope, timing, and read-only behavior. Every sentence adds value and none are redundant filler.

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 single-parameter tool with an output schema, the description is effectively complete. It covers the purpose, the input scope, the expected time cost, the safety profile, and the main output details. The output schema handles detailed return values, so no additional return description is needed.

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% and the existing url parameter description already gives a format example. The tool description adds meaningful constraints on the URL semantics: it must be a public website, and while UK local businesses are the focus, any public site works. This goes beyond the schema but stops short of explaining URL normalization or invalid-input behavior.

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 description clearly states a specific action ('scan') and resource ('public website') and explains the output: a 0–100 score with SEO, GEO, local, trust, conversion, speed, pass/fail checks, priority fixes, and an agent-readiness score. This distinguishes it from siblings like get_page and list_services without requiring the agent to inspect schemas.

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 description explicitly says when to use the tool: when someone asks how good a website is, why it is not being found, or what to fix first. It also scopes the audience ('UK local businesses... but any public site works'). However, it does not explicitly say when NOT to use it or name alternatives such as get_page or list_services, so it misses the 'when-not/alternatives' criterion for a 5.

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