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

Annotations already declare readOnly/idempotent/non-destructive, so the burden is lower; the description goes further by disclosing the scoring model's inputs, the evidence[]/coverage[] output structure, and the conditional nature of the internal predictor. It does not state latency, rate limits, or behavior when data is missing beyond coverage[], keeping it shy of a 5.

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?

Single dense paragraph that front-loads the definition, then enumerates contributing signals, then closes with the crucial scope caveat. It is on the long side and the middle signal list could be trimmed, but every clause carries information.

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 an output schema present, return values need not be explained, yet the description usefully explains what the score means and how evidence[]/coverage[] should be read. It is complete enough to invoke correctly; only explicit sibling routing is missing.

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?

Only one parameter, and the schema already documents it at 100% coverage including the Brazilian registration format and length bounds. The description adds no syntax or format detail beyond the schema, so the baseline of 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 ('Score 0-100 of how likely one registration is to reach the market') and then explicitly bounds the claim ('It is not a prediction of sale: it ranks who to contact first'). The siblings contain no direct duplicate, so the lack of a named alternative is a minor gap rather than a confusion risk.

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?

Usage is only implied — the closing sentence ('ranks who to contact first') hints at lead-prioritization use, but there is no explicit when-to-use, when-not-to-use, or pointer to a sibling such as jt_aircraft_lookup or jt_owner_profile for raw facts. An agent can infer intent but must reason about it.

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