lock_phone

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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it does so well. It discloses that the lock persists until unlocked, that every subsequent tool call acts on this phone, and that requests naming another phone are refused rather than redirected. This is critical state-changing behavior that an agent must know before calling.

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 compact and front-loaded: the first sentence states the core behavior, and the second adds the crucial safety rationale and failure mode. There is no redundant wording or filler.

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?

Given this is a simple one-parameter state-changing tool with no annotations, the description covers the essential behavioral contract, duration, refusal behavior, and intended usage context. Some minor ambiguity remains around the exact value expected for 'name', but the overall definition is sufficient for an agent to invoke it 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?

Schema description coverage is 0%, so the description must compensate for the undocumented 'name' parameter. It implicitly establishes that 'name' identifies the phone to lock ('a request naming a different one'), but it does not specify the expected format, whether it is a device ID or display name, or where valid values come from.

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 explains that the tool restricts all subsequent tool actions to a single phone until explicitly unlocked, and that requests for other phones are refused rather than redirected. This is a specific behavioral contract and not a tautology, though it does not explicitly name sibling tools like unlock_phone to differentiate them.

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 explicitly states when to use the tool: when helping one person, to prevent a misread instruction from reaching another user's phone. It also implies when it stops applying ('until unlocked'), though it does not explicitly contrast with alternatives such as use_phone or list_phones.

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