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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real behavioral value beyond them: 'deterministic' signals repeatable results, and the checklist tells the agent what the tool actually fetches and inspects. It stops short of disclosing latency, request volume, or timeout behavior for a live-crawl tool.

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 sentences, zero filler. The core action and scope come first, with the check list as supporting detail. Nothing reads as redundant.

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 enumerated checks usefully stand in for describing what the audit returns, and annotations cover the read-only/open-world profile. The remaining gap is operational: nothing says how long the audit takes, whether it is synchronous, or what happens on an unreachable URL.

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 schema description coverage is 100%, so the schema documents 'url' fully with an example. The description still adds semantics the schema does not: the URL must be a *public* website, implying private, internal, or credentialed URLs are out of scope.

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 states a specific verb ('Run') and resource ('technical SEO audit') scoped to 'a public website URL', then enumerates exactly what is inspected (canonicals, title tags, robots.txt, redirects, crawl traps, indexability). No sibling tool covers SEO, so the agent can route here unambiguously.

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 the 'public website URL' constraint, which tells the agent this is not for authenticated or private pages, but there is no explicit when-to-use guidance, no statement of prerequisites, and no alternatives to consider. Adequate but thin.

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