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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add what they don't. It does: it discloses the data provenance (cwsi.net's calculator plus the airline's published rules) and adds an 'Unofficial' accuracy caveat, which is exactly the kind of trust/reliability context an agent cannot get from structured fields. It stops short of noting any precision or rate-limit limitations.

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 tightly packed sentence plus a one-word disclaimer. The core purpose (what a ticket earns) is front-loaded, and nothing is repeated or padded.

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?

With an output schema present, return values need not be explained, and all four parameters are fully documented. Provenance and the unofficial-status disclaimer round it out; the only real gap is the absence of guidance on when to pick this tool over nearby siblings.

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 enums documenting card, status, and channel, and price defining qualifying spend. The description adds no parameter-level detail beyond the schema, so the baseline 3 for schema-driven parameter documentation 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?

Specific verb (Estimate) plus the exact resource and scope (what a Sun Country Airlines ticket earns, including miles/points and status credit). Among ~50 airline-specific calculator siblings, the airline name plus the earn-type scope is enough to identify this tool without opening any schema.

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?

Usage is only implied: an agent can infer this is the calculator for Sun Country earnings. There is no explicit when-to-use/when-not, nor any routing to adjacent tools such as compare_fare_classes or calculate_flight_distance for pure distance needs.

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