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

Annotations already carry the safety profile (readOnly=false, idempotent=false, destructive=false). The description adds context that a trip acts as a notebook holding photos and timeline blocks, though it does not disclose behavioral details such as default date/timezone handling or duplicate-trip 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?

Two short sentences with no filler. The action is front-loaded and the conceptual model is conveyed in one clause, so every phrase earns its place.

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 a simple create-with-title tool with full schema coverage and annotation context, the description plus schema is sufficient for correct invocation. It provides useful anchoring of what a trip represents, though a short pointer to update_trip for later modifications would round it out.

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 100%, with title, end_date, start_date, and default_tz_offset all already described. The tool description adds no parameter-level meaning beyond the schema, so the baseline of 3 applies.

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 uses 'Start a trip' as the verb+resource and adds a conceptual model with 'one journey, one notebook,' making it clear this is the trip-creation entry point. It does not explicitly differentiate from update_trip, but 'start' versus update is reasonably distinct.

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?

No guidance is provided about when to use this tool versus alternatives like update_trip or set_trip_*. An agent must infer from the name alone that this is the creation operation.

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