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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, covering the safety profile. The description adds that the result is an estimate based on cwsi.net's calculator and published rules and is 'Unofficial' — useful context about reliability. It does not contradict the closed-world annotation despite mentioning an external calculator as methodology source.

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?

A single front-loaded sentence that leads with the action and resource, followed by methodology and the 'Unofficial' caveat. No filler or repetition. Slightly dense parenthetical but nothing wasted.

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 values need not be described, and all four parameters are fully covered by the schema. For a self-contained pure-calculation tool, the description supplies the essentials (what it computes, methodology, unofficial status). Only the lack of routing versus sibling airline calculators leaves a minor gap.

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 enum meanings spelled out for card, fare, and status and a detailed note on what price includes/excludes. The description adds no parameter-level detail beyond this, so the baseline 3 for a fully documented schema is appropriate.

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) and resource (what a Frontier Airlines ticket earns in miles/points plus status credit), so the agent immediately knows the output type. The airline specificity distinguishes it from the large sibling family of airline calculators. It does not, however, explicitly route against any named alternative.

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 says what the tool does but never states when to pick it over a sibling or any prerequisite (e.g., must be a Frontier booking). With ~50 near-identical calculators, some routing guidance would materially help; none is given, leaving usage to be inferred from the tool name.

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