Get time by app category

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

With no annotations, the description carries the full burden. It explains categorization logic (internal mapping, uncategorized fallback) which is critical for correct interpretation. It does not mention whether it's read-only, but that is implied by 'get' in the name.

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?

Three well-structured sentences. Each sentence adds value: purpose, internal grouping, and uncategorized behavior. No fluff, but it could be slightly more front-loaded with the main action.

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?

The description explains the categorization and uncategorized handling, but with no output schema, it fails to describe the return format (e.g., list of categories with hours). For a 5-parameter tool with moderate complexity, this is a notable gap.

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?

Since schema description coverage is 100%, the baseline is 3. The description does not add extra meaning beyond what the schema already provides for parameters like period, hour filters, or device.

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 it rolls up app totals into broad categories and gives examples like 'creative work vs coding', distinguishing from per-app breakdown. However, it does not explicitly name sibling tools like get_app_breakdown for contrast.

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 description implies usage for high-level questions ('how much creative work vs coding?'), which provides context. But it does not explicitly say when to use this tool versus alternatives like get_app_breakdown, nor does it mention any prerequisites or limitations.

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