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

Annotations already declare read-only, idempotent, non-destructive, and closed-world. The description adds valuable context beyond that: result ordering (newest first), limit (up to 50), return shape (trips[], fields, new_trip link), empty-account behavior, and that it takes no arguments. However, it doesn't go into pagination or error handling, leaving a minor gap.

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?

Front-loaded with the core purpose and key constraints (ordering, limit). Every sentence earns its place: return shape, empty-state behavior, and alternatives are all packed efficiently without waste.

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 fully describes the return value: trips[] with id, name, place, start/end, open links, new_trip link, and empty-account message. It also covers the absence of arguments and provides clear sibling routing. Nothing an agent needs to call it correctly is missing.

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?

The tool has zero parameters, so there is no parameter semantics to explain. The description redundantly confirms 'takes no arguments' but adds no extra meaning. Baseline 4 is appropriate for a no-param tool.

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 (Lists) and resource (trips in the signed-in account) with scope details: newest first, up to 50. It distinguishes itself from siblings by naming get_trip, update_trip, open_trip_form, and start_trip.

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?

Explicitly says to use it to find a trip_id, then points to get_trip for reading days or update_trip for renaming/deleting, and mentions open_trip_form/start_trip for planning a new trip. Clear when/when-not and alternatives.

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