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

Annotations already declare destructiveHint=true, covering the safety profile. The description adds a permission constraint (owners can't leave) which is useful context. However, it does not disclose side effects such as removal from the member list or potential failure conditions. Given the annotation coverage, this is adequate but not rich.

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 a single, front-loaded sentence with a clarifying clause, conveying the essential action and a key exclusion with no wasted words. It is concise and well-structured.

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 tool with one parameter and no output schema, the description covers the core purpose and a critical restriction. It does not describe return values or failure modes, but these are less critical given the tool's simplicity and the presence of destructiveHint annotation. The description is complete enough for the agent to use the tool correctly.

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?

With 0% schema description coverage, the description must compensate. It does not explicitly define journey_id, but the tool name and purpose make it inferable as the ID of the shared trip. For a single simple parameter, this is acceptable, though more explicit documentation would improve clarity.

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 action (leave) and the resource (a trip shared by someone else), and explicitly distinguishes from deletion: 'Owners can't leave their own trip — they delete it.' This differentiates it from sibling tools like delete_journey and makes the 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 provides a clear when-not by stating owners cannot use this tool and should delete instead. It implies when to use (when you are a non-owner of a shared trip) but does not explicitly mention alternative tools like remove_journey_member, though that tool is likely intended for owners to remove others. The guidance is solid but not exhaustive.

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