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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds significant behavioral context: it warns that results are 'observational' and 'not a guarantee', clarifies that 'a user-agent is a claim, not a credential', and discloses cost implications (unknown URLs free, known URLs metered). This goes well beyond annotations and prepares the agent for the tool's limitations.

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 a single, dense sentence that front-loads the core purpose and then compactly adds cost, observational nature, and an important caveat. Every clause earns its place—there is no filler or redundancy. It is concise yet information-rich.

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 tool with one parameter, full schema coverage, and annotations covering safety, the description provides the essential context: what it does, how it behaves (observational/caveats), and cost implications. It does not specify the exact output format, but given no output schema, it should at least hint at what the summary contains—which it does ('summary to branch on'). This is sufficient for an agent to call it correctly.

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% and the single 'urls' parameter has a description that already covers limits (up to 200) and protocol (http or https). The tool description doesn't add meaning beyond the schema for this parameter; it only reinforces what is already structured. Since the schema handles the load, baseline 3 is appropriate.

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 clearly states a specific action: 'Check up to 200 URLs in one call for AI-crawler access', and details the three categories of outcomes (readable, refuse, paid tollgate). It distinguishes itself from siblings by its batch size and summary output, making its purpose unambiguous and differentiating it from tools like check_ai_crawler_access or verify_ai_crawler.

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 provides when-to-use guidance by stating 'with a summary to branch on before spending a fetch' and explains cost behavior for unknown vs known URLs. This implies it's a pre-flight triage step, though it doesn't explicitly name alternative tools or exclusion conditions. The context is clear enough for an agent to select it appropriately among siblings.

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