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

Annotations already carry readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond them: the corpus size (~60 GA types), that airliner results are expressed per passenger, and that business jets are included — all of which shape how an agent interprets matches.

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?

Three sentences, purpose front-loaded, then input formats, then dataset scope — each sentence carries distinct information and there is no filler or repetition of the title.

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 the description needn't explain the return shape, and it still briefly notes the CO₂-per-flight-hour payload. The only real omission is any guidance on result cap or how to widen/narrow the search, which leaves a small gap for a search tool with a 'limit' parameter.

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 baseline is 3, but the description earns a bump by giving worked query examples ('Cessna 172', 'Skyhawk', 'C172', 'PA28') that show the accepted value formats. It still says nothing about the limit parameter's behavior, which the schema handles on its own.

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 ('Finds the aircraft types TrimCarbon has figures for') and enumerates the three query forms — name, ICAO designator, page slug — with concrete examples. Nothing among the siblings (estimate_*, get_*, import_logbook) could be mistaken for this lookup.

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: it is clearly a prerequisite lookup for the CO₂-per-hour figures that the estimate_* siblings consume, but the description never says to call this before estimate_fuel_burn/estimate_flight_hours, nor does it state when not to use it. No alternative retrieval path is named.

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