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

Adds real behavioral context the annotations cannot express: results are cached for a few minutes, so repeated calls for the same flight return the same payload, implying 'call once per flight per answer.' It also notes the response text carries the provider's last-update time, which sets freshness expectations beyond readOnly/idempotent hints.

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 tight sentences, front-loaded with purpose then usage then the caching caveat, which is exactly where an agent needs it before deciding to re-call. No filler.

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-value description is unnecessary; annotations cover safety and open-world behavior; the description covers caching and data-freshness semantics. Nothing an agent needs to call this correctly 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?

Schema coverage is 100% and both parameters are documented there, including the 'id' alias for segment_id, so the schema does the heavy lifting. The description adds no extra meaning about the identifier's origin or the alias behavior, so 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 precise verb+resource+scope: 'current flight status for an existing flight segment in a user's trip.' That scope phrase implicitly separates it from siblings like flight_route_lookup (schedules/routes) and get_flight_airport_conditions (airport-level, not a saved segment).

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?

Gives concrete triggering situations ('delayed, canceled, on time, boarding, or gate/terminal updates'), which is clearer than generic context. It stops short of naming an alternative for adjacent cases (e.g. airport conditions or route lookups), so it lacks explicit when-not guidance.

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