Flight fare details

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

Annotations already declare readOnly/idempotent/destructive=false, so the safety profile is covered. The description adds genuinely useful behavior: that it re-runs the prior search, the meaning of baggage_checked_with_airline, and the refund formula (paid x (100 - penalty_pct) / 100) plus penalty_text fallback.

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 purpose in the first sentence, followed by dense semantic detail. The second paragraph is information-rich rather than padded, though the inline field semantics make it slightly denser than ideal.

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 fare-detail lookup with 8 params, an output schema, and full annotation coverage, the description supplies enough context (search dependency, field semantics, refund math) to call it correctly. It would be stronger with an explicit note on when to use it versus sibling fare tools.

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 every parameter is already documented, including the flight_id format and the ALL-suffix codes. The description only indirectly references the party (adults/children/infants) and round-trip context, adding little beyond the schema, so the baseline 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 ('every fare of one flight') and enumerates what is returned (refund penalties, baggage, fare rules, notes, per-passenger prices). It also names the sibling mb_search_flights and explains the relationship, so an agent can distinguish it from the search tool.

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 clarifies this re-runs the mb_search_flights search with the same route/date/party and returns the chosen flight, which tells the agent when it applies. However, it does not explicitly state when to prefer this over other fare-related siblings (e.g. mb_flight_price_calendar) or any prerequisites.

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