android_file_stat

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint: false, but the description adds behavioral context beyond that: 'without UI' implies no screen interaction, and 'authorized root' suggests permission constraints. These are useful and not present in annotations.

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, tight sentence with zero fluff. Key action ('Read') is front-loaded, and the essential context (metadata, authorized root, no UI) is packed efficiently. Every word earns its place.

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 read-only stat operation with only two parameters, the description gives the core purpose, but it omits what metadata is returned (no output schema) and does not explain parameter roles or edge cases (e.g., missing file). Given the lack of schema descriptions, this is a minimal but incomplete context for an agent.

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 0% and the description adds no parameter-specific meaning. It mentions 'authorized root' which loosely relates to rootId, but gives no details on path or rootId semantics, units, or expected values. The description completely fails to compensate for the schema's lack of documentation.

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 'Read file or directory metadata within an authorized root without UI' uses a specific verb (read) and resource (file/directory metadata), and clearly distinguishes from siblings like file_read (content) and file_list (listing). The 'authorized root' context further clarifies scope.

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 usage context is implied – you'd use this when you need metadata rather than content or listing – but there is no explicit guidance on when to prefer this over other file tools or any exclusion criteria. No alternatives are named, leaving the agent to infer from the sibling set.

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