Lock vehicle

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

Goes well beyond the annotations: it explains that this is a physical actuation, imposes a human-confirmation gate, and — critically — decodes the response 'confirmed' vs 'unconfirmed' semantics, telling the agent to report uncertainty honestly rather than assume success. That response ambiguity is exactly the kind of context annotations cannot convey, and it is consistent with destructiveHint=true.

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?

Three sentences, each front-loaded with its purpose: what it does, the safety gate, then the response interpretation. Zero filler and the confirmation requirement appears before the calling detail.

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 one-parameter, non-idempotent mutation with no output schema, the description covers effect, precondition, and result ambiguity, which is nearly everything an agent needs. Missing only edge cases such as what an error or already-locked vehicle looks like.

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?

Single parameter with 100% schema description coverage ('The vehicle id from list_vehicles'), so the schema already carries the semantics. The description adds nothing about the parameter, which is the expected baseline here.

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 (lock) and resource (the vehicle) plus the physical effect (door locks actuate), so the agent knows exactly what happens. It never names the obvious inverse sibling unlock_vehicle, but the verb/resource pairing is unambiguous enough on its own.

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?

Gives a hard precondition — explicit human confirmation is required before invoking — which is the single most important usage rule for this tool. It does not contrast with unlock_vehicle or discuss when locking is inappropriate (e.g., vehicle in motion), so it stops short of full when/when-not guidance.

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