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

With no annotations, the description carries the full burden. It discloses the key behavioral trait: timing is evenly spaced and not real transcription, and instructs the agent to communicate this to the user. It also mentions that blank lines are skipped and that long lines can be split, which are useful behavioral details. It doesn't mention output encoding or whether the SRT is returned as a string or file, but the core caveat is well covered.

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 sentences, front-loaded with the main action and the critical caveat. Every word earns its place; no fluff or repetition of schema details.

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 simple conversion tool with 100% schema coverage and no output schema, the description covers the essential behavior and the important caveat about timing. It could mention what the output looks like (e.g., SRT content returned as a string) but the absence of an output schema makes that less critical. The sibling list shows related tools, and the description's caveat helps distinguish it from retime_subtitles.

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 schema already documents all four parameters. The description adds context about the overall behavior (evenly spaced timecodes) but doesn't add per-parameter meaning beyond the schema. 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?

The description states a specific verb ('Turn'), a clear resource ('plain transcript' → 'SRT file'), and the key behavior (evenly spaced timecodes). It also distinguishes itself from real transcription tools by explicitly saying timing is a starting point, which helps differentiate it from siblings like retime_subtitles or convert_subtitle.

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 clearly implies when to use this tool: when you have a plain transcript and need an SRT with placeholder timing. It also tells the agent to disclose the synthetic timing when presenting results. However, it doesn't explicitly name alternatives or state when NOT to use it (e.g., when real timing is needed), so it falls just short of a 5.

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