Unlock the trunk

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

Beyond the annotations (readOnlyHint=false, destructiveHint=true), the description adds meaningful behavior: it unlocks only the trunk, leaves doors locked, verifies against the car's reported state, and defaults to preview mode. This exceeds the bare annotation signal and helps the agent understand side effects.

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 compact sentences carry all essential information with no filler. The tool's purpose, safety constraint, and usage pattern are front-loaded and easy to parse.

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 low-complexity tool with one optional parameter, full schema coverage, annotations, and an output schema, the description is complete. It covers what the tool does, when to use it, and how the confirm parameter should be handled.

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%, so the schema already documents confirm. The description adds a decision rule beyond the schema: preview with confirm=false unless the user already confirmed. This enriches the parameter's meaning and usage context.

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 identifies a specific action and resource: 'Unlock the trunk only.' It also differentiates from siblings like toyota_unlock_doors by noting 'doors stay locked,' and the verb 'unlock' distinguishes it from toyota_lock_trunk.

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?

It gives clear invocation guidance: only on the user's explicit request, and with confirm=false as a preview unless the user has already confirmed. It does not explicitly name sibling alternatives like toyota_lock_trunk, but the context is sufficient for choosing when to call this tool.

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