get_app_usage

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

With no annotations, the description must carry the burden of behavioral disclosure. It does add the 'Defaults to today' behavior and specifies that the output is a breakdown of app usage and durations, but it does not explain timezone handling, formatting, permissions, or any potential limitations.

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, information-dense sentence with no filler. Every word contributes: it names the verb, the resource, the output, and the default behavior.

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 tool with one optional parameter and no output schema, this is nearly complete: purpose and default behavior are clear. Minor gaps remain in that it does not describe the exact return format or explicitly differentiate from sibling activity tools.

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 input schema already fully documents the single optional 'date' parameter at 100% coverage, including the default value. The description merely repeats 'Defaults to today' and adds no additional semantic detail beyond what the schema states.

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 states a specific verb ('Get') and resource ('a breakdown of which apps you used and for how long'). This distinguishes it from siblings like get_timeline or get_recent_activity, which focus on different types of data.

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 only usage context is 'Defaults to today', which is a time behavior rather than a comparative guideline. It does not state when to prefer this over sibling tools or list any exclusions, though the intended purpose is strongly implied by the tool name and description.

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