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

No annotations exist, so the description carries the full burden. It does add valuable behavior beyond the schema: the result is an integer number of cents, and prices cover the whole group. It does not state that this is a non-mutating lookup, that omitting origin drops the flight line, or how invalid inputs (non-Friday date, unknown slug) are handled.

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 dense sentence that front-loads the output unit and then enumerates what is priced. No filler, though the colon-and-comma list runs long enough that a second sentence splitting inputs from outputs would read better.

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?

For an 8-parameter computation tool with no output schema and no annotations, the description covers the output unit and cost categories but leaves gaps: it never says what the returned object looks like beyond a number in cents, whether the flight cost is conditional, or what happens on invalid input. Adequate, not complete.

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% — every one of the 8 parameters has a description, enums, and defaults — so the baseline is 3. The description merely restates the axes (tier, month/year mean, group) the schema already documents in richer detail; the '$' unit and 'integer cents' phrasing is the only real addition.

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+resource: a budget estimate in integer cents for a published itinerary, enumerating the cost lines (activities, lodging, transport, flights) it aggregates. This distinguishes it from get_fare and estimate_all in substance, but never names those siblings, so the agent must infer the boundary.

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 phrase 'for a published itinerary' implies usage context, and 'for a tier, a month or the year average, and a group' hints at the parameter combinations that drive the result. However, there is no explicit when-to-use vs estimate_all or get_fare, and no statement of prerequisites (that city/persona slugs must come from list_cities/list_personas) or exclusions (e.g., flights require an origin).

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