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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds critical info: these are indicative quotes for planning, not live bookings. This goes beyond annotations by clarifying the tool's 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?

The description is two sentences plus a note, all front-loaded with key actions and limitations. No unnecessary words.

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?

Given 8 parameters and no output schema, the description covers the main use case and limitation but lacks details on parameter relationships (e.g., how pickup_datetime ties to flight arrival) and return format. Still adequate for a search tool.

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 coverage is only 25% (city and pickup_datetime described). The description does not add any parameter-specific meaning beyond the schema. For a tool with 8 parameters, this is a significant gap.

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?

The description explicitly states 'Search ground transportation' with specific examples (rideshare, car rental) and ties it to flight arrivals. It clearly distinguishes from sibling tools like search_flights and search_hotels.

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 'Use this when the user wants to scope a rental car, an airport transfer, or rideshare to/from their hotel.' It also includes a note that booking is not yet live, which informs when not to use for actual booking. No explicit alternatives are named, but the usage context is clear.

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