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

With no annotations, the description carries the behavioral burden and does well: it discloses that the phone shuts down, billing stops, apps/data/logins remain, and apps start fresh after start_phone. It omits permission or authorization requirements, but covers the key state effects.

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 three short sentences with no wasted wording. The core operation is front-loaded, followed by consequences and the key usage constraint.

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 one-parameter tool with no annotations and no output schema, the description provides enough behavioral context to call it correctly. It does not explain return values or permission requirements, but those are not essential for this simple operation.

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 phone_id parameter is already documented in the schema. The description does not add syntax or format details beyond that, which is acceptable given the high schema coverage 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 states a specific action and resource: parking a phone, with its core effect of shutting it down and stopping billing. It also distinguishes parking from permanent removal by noting apps, data, and logins stay, and names start_phone as the resume path.

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?

It gives clear usage guidance with the condition 'Park only a phone you will resume,' and it points to start_phone for resuming. It does not explicitly contrast with delete_phone for permanent removal, but the intended use case is clear.

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