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

With no annotations, the description carries full behavioral disclosure. It clearly states the return payload shape, explains the handling of missing paths (exists=false rather than an error), and asserts that the call is 'cheap' — a performance characteristic. This goes well beyond a typical description.

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, zero filler. The action is front-loaded, followed by the return contract and the key edge case. Every clause earns its place; no redundancy.

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, no-output-schema tool, the description is fully adequate. It covers the return fields, the non-error missing-path behavior, and the practical use case. Nothing an agent needs to successfully call this tool is omitted.

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% (udid and remotePath both have detailed descriptions). The tool description adds no parameter-specific meaning beyond what the schema already provides (e.g., absolute path example already in schema). Thus, baseline 3 applies.

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?

Description states a specific verb ('Get'), resource ('metadata for one file or directory'), and the exact fields returned (type, size, modification time). It also names the sibling counterpart (ios_file_stat), distinguishing the platform target. This is unambiguous and easily differentiable from the many device_file_* tools.

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?

Provides an explicit use case: 'this is the cheap way to check for a file before pulling it', guiding agents on when to invoke this tool. It also references ios_file_stat as a counterpart, implying platform-specific selection. Lacks a clear 'do not use when' exclusion, but the guidance is concrete enough for correct routing.

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