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

Adds substantial behavior beyond the annotations: paid in USDC from the configured wallet, constrained to budget caps, per-call price and product code, and an explicit third-party-data/not-instructions safety note. It does not reconcile how 'Buy' coexists with readOnlyHint=true, which is the only real gap.

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-loads the core action and price, then layers payment and safety notes densely with no wasted sentences. The parentheticals are slightly busy but each carries distinct information.

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 no output schema and four parameters, the description covers payment mechanics, budget caps, required inputs, and prompt-injection safety. What the returned bundle looks like is not described, but the operation is otherwise callable correctly from this text.

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%, so all four parameters (trip, resort, country, confirm_over_cap) are already documented in the schema. The description reinforces tripId provenance but adds no syntax or format detail 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 and resource ('Buy every remaining step of a ski trip in one call') and scopes it as a bundle purchase priced per trip. An agent can immediately distinguish it from ski_trip_step (single step) and trip_map (free lookup) without opening a 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?

Gives concrete context: take the bundle price from trip_map, pass the tripId from trip_map, and the price/call. It does not explicitly say 'use ski_trip_step instead when you only need one step,' so routing is implied rather than stated, but the trigger conditions are clear.

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