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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses two important behaviors beyond the schema: both paths must be within the same root, and missing parent directories of the destination are automatically created. While it does not mention overwrite behavior or error conditions, the disclosed constraints and auto-creation behavior are substantial and relevant for safe invocation.

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 three sentences long, front-loaded with the core purpose, and every sentence adds value. It efficiently conveys the operation, the key constraint and alternatives, and an important behavioral detail without redundancy or fluff.

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 mutation tool with no output schema and no annotations, the description provides critical context: the same-root restriction, the cross-root alternative, and automatic parent directory creation. It does not describe the return value or overwrite semantics, but these are not essential for tool selection and invocation. Overall, it is sufficiently complete for common use cases.

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 baseline is 3. The description adds meaningful semantics beyond the schema by clarifying that remotePath and to are within the same root and explicitly stating that missing parent directories for the destination are created. This helps the agent understand the relationship between parameters and the tool's behavior during invocation.

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 function with a specific verb and resource: 'Rename or move a file or directory on an iOS device.' It further distinguishes itself from related tools by explicitly noting the same-root constraint and referencing ios_file_pull/ios_file_push for cross-root operations, making it unambiguously different from siblings like ios_file_copy.

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 explicitly explains when to use this tool versus alternatives: it states that moving between an app container and the shared media directory should be done with ios_file_pull followed by ios_file_push, not this tool. It also ties the path scope to the same bundleId selection as ios_file_list, giving clear context on the valid usage domain.

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