ass_frame_from_ms

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

With no annotations, the description carries the full burden and does well: it lays out the complete fps resolution fallback chain (argument, workspace video dict/probed path, script config, [Script Info] FPS, then failure) and discloses error behavior (a ToolError explaining what is missing). It does not state whether the call is side-effect-free, but the read-only nature is strongly implied by a pure conversion.

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?

The Args/Returns structure is front-loaded and every sentence earns its place, though the Returns block enumerates keys already present in the output schema, which is mildly redundant. Otherwise efficient and well organized.

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 three-parameter conversion tool, the description covers parameter meanings, the fps resolution chain, failure behavior, and return keys. With an output schema present, there is nothing an agent needs for correct invocation that 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 description coverage is 0%, so the description must compensate entirely, and it does: ms is typed as int/float or a time string, fps is documented along with its full resolution order, and doc_id is clarified as being used only as an fps source. This adds meaning the bare schema (defaults only) does not provide.

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 and resource ('Convert a time in milliseconds to a frame number'), and the directionality is explicit, which implicitly distinguishes it from the inverse sibling ass_ms_from_frame. It does not, however, name that sibling or any alternative, so it stops short of full sibling differentiation.

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?

Usage is only implied by the direction of the conversion; there is no statement of when to prefer this over ass_ms_from_frame, ass_frame_from_timecodes, or ass_snap_to_frames, and no prerequisites or exclusions. Adequate but leaves the routing decision to the agent.

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