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

Annotations already declare destructiveHint=true, readOnlyHint=false, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by explaining the real-world effect (a door physically unlocks) and the user-consent requirement behind confirm. It does not describe the response or failure semantics for a rejected unlock, keeping it below 5.

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?

One compact sentence with the most important signal ('WRITE, SECURITY-SENSITIVE') front-loaded, followed by the use condition, the parameter instruction, and the endpoint. No wasted text.

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 two-parameter destructive mutation, the description covers purpose, consent gating, and the underlying endpoint. It omits any mention of the return payload or what a failed/unauthorized unlock looks like, which would be useful given there is no output schema, but the essential calling information is present.

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%: both device_id (UUID) and confirm (const true) are fully documented in the schema. The description's 'set confirm to true' reinforces the consent contract but adds no format or syntax detail beyond what the schema already states, so the baseline 3 applies.

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 and resource ('sends the unlock command to a lock, which physically unlocks the door') plus the underlying endpoint PUT /devices/{id}/unlock. The physical-unlock consequence makes it trivially distinguishable from the sibling remotelock_lock_device.

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 an explicit precondition ('only call it when the user explicitly asked to unlock this specific door') and a required confirmation gate. It stops short of naming the inverse sibling (remotelock_lock_device) as an alternative, so it earns a 4 rather than a 5.

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