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

With no annotations provided, the description carries the full burden. It discloses the operation's outputs (type, size, modification time), implies a read-only nature, and adds cost/behavior context ('Cheaper than listing a directory'). It does not mention error behavior or permission requirements, but for a metadata lookup the core behavior is transparent.

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?

Two sentences with no filler; the primary purpose is front-loaded and the additional guidance is compact. Every clause adds value, from the metadata fields to the comparative cost to the sibling root-selection reference.

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 stat tool with a well-covered schema, the description provides enough context: purpose, return fields, usage scenarios, and root selection. It lacks exact output formatting and error behavior, but these are minor given the tool's simplicity and the absence of an output schema.

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 schema already documents all parameters well. The description adds a useful cross-reference ('Same bundleId root selection as ios_file_list'), but this does not substantially expand meaning beyond what the schema provides. Baseline 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 opens with a specific verb and resource: 'Get metadata for one file or directory on an iOS device', and enumerates the returned fields (type, size, modification time). It clearly distinguishes itself from ios_file_list and ios_file_pull, so an agent can differentiate it without opening schemas.

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 concrete usage context: use it when you already know the path, to check a file's size before pulling it, and it is cheaper than listing a directory. It references ios_file_list for the bundleId root selection, but it does not explicitly state when not to use it or name a formal alternative for listing paths.

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