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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuinely new behavior: the concrete meaning of idempotency (a missing file is not an error) and a guard condition (it refuses to delete recordings still being written), which the annotations do not express.

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?

Three short sentences, front-loaded with the action and resource, then the input requirement, then the two behavioral caveats. No filler; each sentence carries distinct information.

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 destructive one-parameter tool with annotations covering the safety profile and no output schema, the description covers action, input, idempotency, and the write-in-progress guard. Only minor gaps remain, such as what an error response looks like if deletion is refused.

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% for the single httpPath parameter, and the schema description already states it comes from ios_record_stop. The description reinforces that provenance but adds no new syntax, format, or edge-case detail beyond the schema.

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 ('Delete a finished iOS recording mp4 from disk') with scope qualifier 'finished', which cleanly separates it from ios_record_stop (which produces the file) and generic file deleters like ios_file_delete.

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 an explicit precondition ('call ios_record_stop first') and an exclusion (refuses in-progress recordings), plus the required input provenance. It does not explicitly route the agent away from generic alternatives such as ios_file_delete, but the lifecycle framing is clear enough.

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