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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful caveat — 'Unofficial' — signaling the result is an estimate, not an official carrier figure. It stops short of saying whether output is deterministic or how results should be interpreted.

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?

Two short sentences with the purpose front-loaded and no filler; the one-word 'Unofficial.' fragment is terse and earns its place, though the parenthetical 'miles or points, and status credit where it applies' is slightly hedgy.

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 (return values need not be described), annotations carry the safety profile, and the schema fully documents inputs, so the description only needs to frame scope and reliability. It does so with the data-source note and unofficial disclaimer, leaving only when-to-use 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 description coverage is 100%, with all five parameters, three enums, and per-value multipliers documented in the schema itself. The description adds no parameter-level meaning (it does not explain the base-fare vs. taxes distinction beyond what the schema says), 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 (estimate) plus the exact resource (what a Southwest Airlines ticket earns in miles/points and status credit). The airline name alone cleanly separates it from the ~50 sibling calculate_*_miles/points tools.

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?

There is no guidance on when to call this versus compare_fare_classes, get_fare_classes, or calculate_flight_distance, and no exclusions or prerequisites. The only context offered is the data source ('cwsi.net's calculator and the airline's published rules'), which is not a usage condition.

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