Shut down a phone

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

With no annotations, the description carries the full burden and provides almost nothing beyond the basic mutation. It does not say whether shutdown is graceful or forced, whether unsaved emulator state is destroyed, whether the call blocks until the device is off, or whether it affects one or all devices.

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 zero filler. It is efficient, though its brevity reflects under-specification rather than tight editing of a richer explanation.

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 state-changing lifecycle tool with no annotations and no output schema, the description omits essentials: what state is lost, whether the operation is reversible, and what the agent should expect afterward. The simple one-parameter schema keeps the bar low, but the behavioral gap is still material.

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%, so the single optional `serial` parameter is already fully documented in the schema, including the 'only needed when several are connected' nuance. The description adds nothing about it, which is acceptable given the schema does the work, but earns no credit above baseline.

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 names a specific verb and object ("shut down a running emulator"), which is unambiguous and distinct from the sibling phone_start. It stops short of explicitly naming the counterpart tool, but the resource is concrete enough that an agent can tell what it does without reading 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?

"Running emulator" implies a precondition, but the description never states when to call this versus alternatives, whether it should be paired with phone_start, or what to do if nothing is running. There is no routing guidance relative to the 17 sibling tools.

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