screenstudio_voice_lines

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

Annotations only declare the safety profile (readOnlyHint false, openWorldHint true, destructiveHint false); the description adds material context beyond them — the edge-tts online dependency with the privacy note that 'the text leaves this Mac', the caching of clips, and reuse by screenstudio_narrate keyed on text/voice/rate. It also documents the return values, which no output schema supplies.

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?

Front-loads the purpose and stays to one dense sentence with parentheticals. Efficient, though the parenthetical stack makes it slightly heavy to parse.

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?

With no output schema, the description correctly supplies the return shape (durationMs, beatMs) plus the network/privacy and caching behavior, which is what an agent needs. Minor gaps remain on failure modes (e.g., what happens if edge-tts is unreachable), but the core is complete.

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 67%: rate and voice already carry descriptions with defaults and re-sync behavior. The description only adds that the cache key is (text, voice, rate), which is useful but marginal, so baseline 3 is appropriate.

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 ('Voice a script before recording, without a project') and names the return payload (durationMs, beatMs). It explicitly distinguishes itself from siblings screenstudio_desktop_perform and screenstudio_narrate, so an agent can route without opening the 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: voice a script BEFORE recording and without a project, so each beat can be recorded to match its line length. It names screenstudio_narrate as the tool that reuses the cached clips, implying the when-to-use split, but stops short of an explicit when-not-to-use rule.

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