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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond them: the audit is static-HTML-only (no JS rendering) and respects robots.txt, which materially affects expectations of results.

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?

A single dense sentence, front-loaded with the core purpose before the checklist of checks. The long enumeration earns its place by telling the agent exactly what output to expect, though it pushes toward run-on length.

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 compensates by summarizing the return payload (issue list and 0-100 score) and states key limitations. Coverage is strong for a one-parameter tool, though it never mentions error cases for unreachable URLs.

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% with a single, self-explanatory 'url' parameter, so baseline is 3. The description adds value by clarifying that only one page is audited per call, which shapes how the agent uses the parameter.

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+resource ('Technical SEO audit of one page') and enumerates the exact dimensions checked, so an agent can immediately distinguish it from siblings like site_contacts or url_markdown.

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 implied by 'of one page' and the constraint 'Static HTML only; honours robots.txt', but there is no explicit statement of when to pick this over sibling tools or what prerequisites exist. The agent must infer scope from context.

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