Get usage duration statistics

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

With no annotations provided, the description must fully convey behavioral traits. It only states a basic read operation without disclosing whether it is read-only, any side effects, rate limits, data freshness, or error conditions. This is severely lacking for safe invocation.

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, well-structured sentence that gets straight to the point. It is appropriately concise, though it could be slightly expanded without losing its compactness to improve other scores.

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?

Given the tool has 5 parameters and no output schema or annotations, the description is far too brief. It omits critical context about return format, pagination, error handling, and interpretation of results, leaving the agent underinformed.

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 description coverage is 100%, so the baseline is 3. The description does not add any additional meaning to parameters beyond what is already in the schema, such as clarifying the difference between 'daily' and 'daily_per_launch' stat types.

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 identifies the tool as getting app usage-duration statistics for a single date. It uses a specific verb ('Get'), a distinct resource ('usage-duration statistics'), and a scope ('for one date'), which effectively distinguishes it from sibling tools like umeng_get_launches or umeng_get_active_users.

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 provides no guidance on when to use this tool versus alternatives such as umeng_uapp_get_durations or other statistics tools. There is no mention of prerequisites, best practices, or scenarios where this tool is preferred.

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