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

Annotations cover the safety profile (readOnly=true, openWorld=true, non-destructive), lowering the bar. The description adds useful input-composition context (registry + flight patterns + overrides) and the fact that assumptions are optional. It doesn't mention caching, rate limits, or precision/confidence.

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?

One dense sentence plus a short benefit clause; the purpose and inputs are front-loaded with zero wasted text.

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?

An output schema exists, so return format need not be explained. Combined with annotations, the description gives enough for correct invocation; only the units/format of override parameters remain unspecified.

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 only 17% (only 'days' documented), so the description must compensate. It enumerates override dimensions (fuel, insurance, hangar, annual hours) that map to undocumented parameters and calls out lookback context, adding real meaning beyond the schema.

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?

Names a specific verb (estimate), resource (cost of ownership for a specific tail), and discloses the data composition (registry data, flight patterns, overrides). Clearly distinguishable from siblings like value_aircraft or analyze_flight_usage.

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?

Explicitly names use cases: pre-buy disclosures and TCO comparisons, which tells the agent when this tool is appropriate. No explicit exclusions or alternative-naming, so not a 5.

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