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

The annotations indicate a write operation (readOnlyHint false) and no destructive flags, but the description does not elaborate on side effects, permissions, or idempotency. Since annotations are present, the bar is lower, but the description adds minimal behavioral context beyond saying it creates a new trip, so a neutral score is appropriate.

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 short sentences with no redundant or unnecessary information. It is well-structured and to the point, making it easy for an agent to parse and act upon quickly.

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?

The description provides sufficient context for a simple creation tool, including when to use it and what it accomplishes. It does not explain return values or error handling, but given the lack of an output schema and the straightforward nature of a create operation, the description is largely 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 coverage is 50% (start_date and end_date have descriptions, name and description do not). The tool description does not mention any parameters or provide additional meaning beyond the schema. Since coverage is not below 50%, a baseline score of 3 is applied.

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 clearly states the tool creates a new trip (journey), using the verb 'start' and resource 'trip'. It also distinguishes this action from adding to an existing trip, which sets it apart from potential alternatives like updating or extending a journey.

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 explicitly indicates when to use the tool: when the user wants a separate trip rather than adding to an existing one. This provides clear guidance versus other tools that might modify or extend existing journeys, and it's concise and directly actionable.

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