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 meaningful behavioral context: it is deterministic and uses no AI, and it discloses the payment model ($0.002 USDC per call via x402 on Base) plus a free tier (first 5 calls per day per client). This cost/auth information directly affects invocation and selection decisions, though rate limits beyond the free tier and error behavior are not covered.

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 front-loaded with purpose and output scope, followed by a compact pricing sentence. The long token enumeration is informative but slightly overstuffed; it earns its place by demonstrating coverage of major AI crawlers. Overall the structure is efficient and each sentence serves a clear function.

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 successfully enumerates what the report contains (robots.txt verdicts by token group, meta robots, X-Robots-Tag, llms.txt). It also covers determinism and cost, which are important for an external-fetch tool. It is missing only minor operational details such as timeout or error handling, so it is nearly complete for correct invocation.

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 description coverage is 100%; the single parameter 'url' is fully documented in the schema with a description and example. The tool description adds no syntax, format, or constraint details beyond saying 'for a URL'. Baseline 3 is appropriate when the schema already carries parameter semantics.

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 ('access report') and resource ('AI crawler access for a URL'), and enumerates exactly what is checked (robots.txt verdicts for 20 AI tokens, meta robots, X-Robots-Tag, llms.txt). This scope clearly separates it from the sibling robots_check (a general robots.txt tool) and sitemap_check. An agent can tell what this tool returns without opening any schema.

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 implies usage by describing the exact scenario (checking AI crawler permissions for a URL) but never explicitly states when to choose it over robots_check or sitemap_check. It adds practical selection context through pricing and free-tier notes, but offers no exclusions or direct alternatives. A 3 reflects clearly implied but unguided usage.

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