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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuinely useful behavior beyond them: results carry both relative and absolute paths, and truncated:true means the walk was stopped by the limit and must be reported as 'first N matches'. This is real disclosure the annotations do not provide.

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?

Five tightly packed sentences, front-loaded with the core purpose and the query semantics, then result semantics, then the truncation caveat. No filler; every sentence conveys a distinct fact an agent needs.

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?

No output schema exists, so the description correctly compensates by describing the return payload (relative + absolute paths) and the truncation flag. Combined with 100% schema coverage and safety annotations, nothing an agent needs to call it correctly is missing.

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 the baseline is 3, but the description adds meaning the schema lacks: it states the match is case-insensitive, gives glob examples (*.log, app-?.db), and clarifies the limit's interaction with results. It does not explain maxDepth or udid beyond the schema, keeping it from a 5.

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?

States a specific verb and resource ('Search an iOS device subtree for files and folders whose NAME matches a query') and explicitly positions it against the sibling ios_file_list ('far cheaper than listing directories one by one'). An agent can distinguish it from ios_file_list and device_file_find without opening either schema.

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?

Gives clear context for when this is the right choice over directory-by-directory listing, and points to ios_file_list for the shared root-selection semantics. It stops short of explicit when-not-to-use guidance (e.g. searching a single known directory), so it is strong but not exhaustive.

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