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

Annotations already declare this is a non-read-only, non-destructive, closed-world write. The description adds only the scoping detail 'connected user settings', which usefully signals the make is user-level data. It does not explain duplicate handling, permissions, or side effects, so it is adequate but thin given annotations carry the safety profile.

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?

A single efficient sentence with the action front-loaded and nothing wasted. It is terse rather than padded, which is appropriate.

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?

An output schema exists so return values need not be explained, but with 0% schema coverage across two parameters and no usage or behavioral detail, the definition is too thin for a write tool that stores user settings.

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 0%, so the description must compensate, but it names neither parameter. The optional teamId in particular is undocumented anywhere, and 'make' format/constraints are never described, leaving real ambiguity.

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?

'Add a custom vehicle make' states a specific verb and resource, and 'vehicle make' distinguishes it from the sibling create_vehicle (which creates the vehicle, not the make lookup). It does not explicitly call out its relationship to create_vehicle or update_vehicle_make, so it stops short of a 5.

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?

There is no guidance on when to create a custom make versus using an existing one, nor any mention of related siblings like update_vehicle_make or delete_vehicle_make. The agent is left to infer all usage context.

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