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

The description adds useful behaviors beyond the readOnly/idempotent annotations: it discloses that an unknown slug returns near matches and that the record includes blocking cost and verification method. This gives the agent expectations for edge cases and output richness. No annotation contradiction.

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 a long JSON-RPC block about calling whoami, which is irrelevant to this tool and constitutes wasted space. The remaining field list is dense and informative, but the confusing preamble reduces clarity and structure.

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 compensates by listing all major return fields (operator, category, robots stance, user-agent example, verification, IP-range endpoint, blocking cost) and the near-match fallback. It is concise enough for a single-slug lookup, although the purpose of the whoami first call is left unexplained.

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?

The schema already documents slug with 100% coverage; the description reinforces it with a concrete example (slug='claudebot') and clarifies handling of unknown slugs. It does not redefine the parameter type but adds practical usage context, which is helpful.

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 the tool returns the full index record for one crawler and enumerates the fields. This distinguishes it from list_crawlers by focusing on a single crawler. However, the opening 'FIRST CALL, needs nothing' JSON-RPC to whoami introduces noise and could mislead about the tool's purpose.

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 no explicit guidance on when to choose this tool over siblings like list_crawlers or classify_user_agent. It implies singular lookup context but does not state exclusions or alternatives. The 'FIRST CALL' instruction suggests a workflow without explaining why, so an agent gets little routing help.

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