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

Annotations already cover readOnly/idempotent/openWorld/non-destructive, so the bar is lower, and the description goes further: it discloses the evidence sources (published IP lists, forward-confirmed reverse DNS, 7 days of observatory network and JA4 data), the $0.005 per-call cost, and the full verdict taxonomy. It stops short of stating rate limits or error behavior, but adds substantial beyond-schema context.

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 question and outcome categories before pricing, sample payload, and return fields. The return-field enumeration is dense but justified given there is no output schema; a couple of clauses (the bot list) could be trimmed without loss.

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 fully by enumerating the returned fields (verdict, confidence, identified_as, checks, observatory) and the verdict enum. Combined with the free sample call, an agent has everything needed to invoke and interpret results.

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%, so baseline is 3, but the description adds meaning by explaining that identity is judged on IP + user-agent and that JA4 is a TLS fingerprint feeding the observatory check — clarifying what each input contributes to the verdict rather than just restating types.

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 and resource ('Verify a crawler's identity') and immediately enumerates the outcome space (real Googlebot/Bingbot/GPTBot, impostor, other bot, human). This is clearly distinguishable from siblings like bot_verify_batch and bot_observatory, which are bulk/observational variants.

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 when the tool is relevant by framing it as a single-visitor identity check with the required inputs, but it never names bot_verify_batch or bot_observatory as alternatives or states when not to use it. The price note hints at per-call economics but not routing guidance.

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