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

With no annotations provided, the description carries the full burden. It explains the return format ({ ok, packageName, apks: [...] }), the split APK behavior (config splits, dynamic feature modules), and the role field values, which is substantial behavioral disclosure beyond the bare schema.

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 dense paragraph, appropriately sized. It front-loads the core purpose, then adds return format details and usage pointers in a logical flow. Slightly verbose with the return JSON but this is concise and valuable information packed efficiently.

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 two-parameter read-only tool with no output schema, the description adequately covers the purpose, return format, and downstream usage (device_file_pull). The success/error behavior (ok flag) is disclosed. Given no output schema exists, the return format documentation partially compensates for that 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?

Schema coverage is 100%, so both parameters (udid, packageName) are fully documented in the schema. The description doesn't add additional parameter semantics beyond what the schema provides, but the schema already fully describes both params, so the baseline of 3 is appropriate.

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 verb (List), resource (APK file paths), and mechanism (`pm path`). It distinguishes itself from sibling tools like device_file_list (which lists files broadly) and device_file_pull (which pulls bytes) by explicitly framing this as an APK-specific path listing tool.

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?

Clearly states the tool returns paths and sizes, and directs users to device_file_pull for fetching bytes with explicit mention of the 5MB cap and 20MB maxSizeBytes. However, it doesn't explicitly state when NOT to use it or name alternatives directly, though the pull tool reference is implied guidance.

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