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

No annotations are provided, so the description carries the burden. It discloses that the tool reads from DropBoxManager and provides aggregate analytics, but it does not mention any side effects (likely none), whether it requires special permissions, or what the output structure looks like. Since it's an analytics/read operation, the description implicitly indicates no destructive behavior, but it doesn't explicitly state that. A more explicit note about being non-mutating would be better, but the current level is adequate.

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 two sentences, front-loaded with the core purpose and scope, and ends with a routing hint to the sibling. Every word earns its place; no fluff or repetition. It is concise and structured effectively for quick scanning.

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 that this is a simple analytics tool with one parameter and no output schema, the description is nearly complete. It tells the agent what data it returns (aggregate stats across multiple dimensions) and when to use the sibling for detail. Missing is the exact return format or whether it returns a JSON object or table, but the tool's complexity is low, so the description is sufficient for correct invocation and basic understanding.

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% for the only parameter (serial), which is described as 'Android device serial (from `device_list`)'. The description does not add more parameter detail beyond the schema, but the schema is already explicit. Given the single parameter and complete schema coverage, the description adds little but the schema handles it well. A baseline of 3 would apply; however, the description's mention of DropBoxManager as a data source provides a bit of context not in the schema, slightly elevating it.

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 the tool's purpose: 'Crash / ANR / native-crash analytics from DropBoxManager', listing the dimensions of analysis (total, per-process, per-type, per-day timeline). It also specifies the data source (DropBoxManager), which distinguishes it from other crash-related tools like android_crash_detail. The verb 'analytics' is somewhat weak but the resource and scope are explicit, making it clear what the tool provides.

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 gives a direct pointer to the sibling tool: 'Use android_crash_detail for one entry.' This clearly tells the agent when to use this tool (aggregate analytics) vs when to use the alternative (single entry detail). However, it does not explicitly state when to use this tool over other analytics tools like ios_crash_analytics (but that's platform-specific) or when not to use it (e.g., for real-time crashes). The context is clear enough for typical use.

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