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

The annotations declare readOnlyHint=false and openWorldHint=true, and the description explains why: 'Uses two reads and saves the result in the user's Puley history', which accounts for the non-read-only profile and the double cost. It also conveys data recency ('live', 'right now'), but does not cover rate limits, quotas, or failure behavior.

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?

Content is front-loaded on what is returned, then parameter semantics, then the side effect. It is dense but each clause adds information; the colon-separated parameter notes are slightly run-on, which costs a point.

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, the description adequately enumerates the fields an agent would receive and notes sorting and price-level assessment. The only substantive gap for a 6-parameter tool is the undocumented 'nonstop' flag and no indication of result limits.

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 0%, so the description carries the full burden and mostly does: it defines origin/destination as a city or airport code, gives the YYYY-MM-DD format for depart/return_date, explains the one-way omission, and gives currency examples. The 'nonstop' boolean is the one parameter left undefined.

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 (live fares from Google Flights for a route and dates) plus the exact returned fields: price, airline, stops, times, duration, layovers, sorting and Google's price-level verdict. This clearly separates it from siblings like flight_status (status of a specific flight) or find_cars/find_stays (other travel verticals).

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 implied through the parameter-level guidance ('no return_date for one way'), which tells the agent how to handle one-way searches. However, it never states when to prefer this over a sibling such as flight_status, ticket_prices or find_stays, nor are any exclusions or prerequisites given.

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