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

Annotations already declare readOnly, idempotent, open-world and non-destructive, so the safety profile is covered. The description adds genuinely new context: it is rate-limited per anonymous identity and returns the same audit shape authenticated users receive, which helps an agent anticipate throttling and output structure.

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?

Three short sentences with no filler, and the core purpose plus the 'public/anonymous' scoping is front-loaded before the secondary notes on output and rate limits.

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 one-parameter read-only tool with full schema coverage and rich annotations, the description covers purpose, output shape and a rate-limit caveat. No output schema exists, but the description gestures at the return shape, so the remaining gap is minor.

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 a single parameter at 100% schema description coverage, so the schema already documents the url argument with an example format. The description adds nothing about the parameter beyond what the schema provides, so the baseline 3 applies.

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 ('Run the anonymous single-URL SEO checker') with a clear scope qualifier (public, single URL). It implicitly distinguishes itself from the authenticated scan sibling via 'Returns the same audit shape logged-in users see', but never names that sibling (e.g. start_scan), so differentiation is inferred rather than explicit.

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 'anonymous/public' framing implies this is the right tool when no credentials are available and the logged-in scan is the alternative, but it never states when to use this versus start_scan. Usage is implied, not spelled out, and no exclusions or prerequisites are given.

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