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

Annotations already cover safety (read-only, idempotent), and the description adds genuinely non-derivable behavior: the model-mode list consumes the daily records quota, results are capped at 50 with full coverage first, total is always returned, and per-capability matchType/scope/alsoMatches semantics are spelled out. It even tells the agent how to present exact versus approximate counts.

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?

Purpose is front-loaded and every block maps to a distinct rule (modes, matching, coverage levels, quota). It is nonetheless dense and parenthetical-heavy, with asides like the '10 h / 1 month' example that add length without changing how the tool is called.

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 two-mode domain tool with zero required parameters, the definition covers input selection, ambiguous-match handling, output field meanings (matchType, coverage, fullRating, fleetSearchModels), and cost. An output schema exists, so the extra return detail is bonus rather than a gap.

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 the schema documents the parameters, but the description adds mode dispatch the schema cannot express: q/com/cnpj select mode 1, model selects mode 2, and model slugs come from jt_model_search or fleetSearchModels. It stops short of explaining the uf narrowing or mixed-identifier precedence.

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 first sentence states a specific verb and resource: what a Brazilian RBAC 145 maintenance shop is rated by ANAC to work on, from its Operations Specifications (airframes, engines, propellers, equipment). It then names two distinct modes so an agent can tell the shop-lookup mode apart from the model-lookup mode without opening the 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?

It explicitly routes: 'Use this when a lead is a maintenance shop', explains why jt_company_search only finds the CNPJ, and excludes jt_owner_fleet as the wrong market basis. It also constrains each call to a single mode, and instructs how to handle ambiguous name matches (offer up to 5 candidates and let the user pick).

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