phone_app_switcher

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 flags the tool as EXPERIMENTAL, explains the primary mechanism, notes a dependency condition, and discloses a fallback path. It stops short of describing expected outcomes or failure behavior if both paths fail.

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 a single efficient sentence with the experimental warning front-loaded and the mechanism plus fallback packed in without waste.

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 simple no-parameter UI action with no output schema, the description is nearly complete: it gives the action, implementation path, fallback, and experimental status. Minor gaps remain around expected outcome and failure handling if both mechanisms fail.

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 has zero parameters, so parameter semantics are inherently simple. The baseline for 0 params is 4, and no parameter-related information is missing.

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 states a specific verb and resource: "Open the iPhone App Switcher." It also names the mechanism (iPhone Mirroring menu) and fallback (imctl gesture), making the action distinct from siblings like phone_home or phone_tap.

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 is implied by the action itself, and the description adds a useful condition: it works without python/pyobjc when the mirror is connected. However, it does not explicitly say when to choose this over alternatives or when not to use it.

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