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

Annotations already declare read-only, idempotent, non-destructive behavior. The description adds important context beyond annotations: booking and payment happen on symone.fr only, and reservation contacts are returned, clarifying that the tool itself does not complete bookings.

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 front-loaded with the core purpose and uses three tight sentences with no filler. Each sentence adds useful information: the two use cases, the route_id effect, and the external booking boundary.

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 explains what is returned: the booking link, reservation contacts, and optional repeated trip details. The annotations cover safety, and the description covers the key behavioral boundary that booking and payment occur externally on symone.fr.

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 the schema already documents both parameters and the need enum. The description reinforces the route_id source and notes that trip details are repeated next to the link, but adds little parameter-level meaning beyond the schema.

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 states a specific verb and resource: get the link to book a scheduled SYMONE trip or request a quote. It also distinguishes the two use cases via the need enum and names the source of route_id, making the tool's purpose unambiguous.

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 clearly explains when to use each mode: scheduled_trip for a trip listed by search_routes, and quote for a route or date that is not listed. It does not explicitly mention when not to use the tool or contrast it with sibling tools beyond the search_routes dependency.

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