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

With no annotations, the description carries the full behavioral burden. The exhaustive scope list implies a read-only fetch-and-analyze operation, which is useful, but it says nothing about network dependency, latency/timeouts, rate limits, or failure modes on unreachable URLs. Adequate implied behavior, no disclosed operational traits.

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-loaded with the core verb+resource, then the audit checklist, then the sibling routing. The catalogue of checks is long, but each item is concrete and non-redundant, so it earns its place; slightly dense as a single block.

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 audit tool with no output schema or annotations, the description covers scope and alternatives well enough to invoke correctly. It does not describe the shape of the returned report, but the enumerated checks largely telegraph what comes back.

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?

One parameter with 100% schema description coverage, so the baseline is 3. The description adds no meaning beyond the schema — it doesn't clarify URL format expectations (scheme, redirects, non-HTML targets) even though 'fetch a URL' hints at network 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?

Specific verb+resource (fetch a URL and run a full on-page SEO audit) followed by an explicit enumeration of what gets audited. It also distinguishes itself from the nearest siblings by naming structured_data_extract and tech_stack_fingerprint and stating the condition under which each is preferred.

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?

States the scope ('whole-page audit') and routes the agent away with named alternatives for two adjacent needs: raw extracted data → structured_data_extract, platform/framework → tech_stack_fingerprint. This is explicit when-to-use plus when-not-to-use guidance.

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