phone_home

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

With no annotations, the description carries the full burden and does well: it discloses the preferred path (iPhone Mirroring menu), the dependency (no python/pyobjc needed when mirrored), the fallback (imctl swipe), and the experimental stability caveat. It omits what happens if both paths fail and whether there is any latency or confirmation, keeping it short of a 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?

A single front-loaded sentence with the EXPERIMENTAL risk flag first, then the action, then the fallback. Dense but every clause (menu path, dependency, fallback) carries real information; the parenthetical is slightly heavy but not wasteful.

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 zero-parameter, annotation-free, output-schema-free action tool, the description covers purpose, precondition, implementation path, and fallback. The remaining gap is failure behavior — what the agent sees if neither the mirror nor imctl succeeds — which matters for an EXPERIMENTAL tool.

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?

The tool takes zero parameters, so the baseline is 4. The absence of an input schema is fully consistent with the description, which describes an action requiring no arguments.

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 destination: 'Go to the iPhone Home Screen', which is unambiguous. It does not explicitly contrast with phone_app_switcher or phone_launch, but the target (home screen) is distinct enough that an agent can pick it without opening the schema.

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?

Usage context is implied rather than stated: the tool is marked EXPERIMENTAL and works 'when the mirror is connected', which hints at a precondition. It never says when to prefer this over phone_swipe, phone_app_switcher, or phone_launch, so routing between siblings is left to inference.

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