Save the recorded test

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

No annotations are provided, so the description bears the full burden. It discloses the file format and that recording continues after saving, but says nothing about whether an existing file at the target path is overwritten, what the tool returns, or whether a save can fail partway — all material for a write operation with zero annotation coverage.

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 short sentences, zero waste, with the core action front-loaded and the non-obvious side effect (recording continues) immediately after.

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?

A simple 3-parameter tool with no output schema and no annotations. The description covers the action and the format but leaves the write semantics (overwrite behavior, return value) unstated, which is a real gap for a file-writing tool.

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%, and each parameter already has a clear description including the default path and the multi-device case for serial. The description adds no parameter-level meaning beyond the schema, so the 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?

States a specific verb + resource + output format: "Write the recording as a Maestro-format YAML flow." That distinguishes it from phone_test_start (begin recording) and phone_test_run (execute), though it never names those siblings explicitly.

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?

"Recording continues, so you can save again later" implies this is a mid-recording snapshot you may repeat, which is useful usage context. But there is no explicit guidance on when to save vs. when to run (phone_test_run) or start a new recording, so the agent must infer from siblings.

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