ass_snap_to_keyframes

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

With no annotations, the description carries the full burden and does meaningful work: it documents skip behavior via max_distance_ms, states that forward_only contradicts mode="previous", and clarifies that count/changes only include fields that actually moved. It still omits mutation side effects (that lines in the document are rewritten) and any undo/permission context, so it stops short of full disclosure.

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 purpose sentence is front-loaded and the Args entries are one line each with no filler. The Returns block is fairly long and duplicates information already carried by the output schema, which costs a little economy but does not obscure anything.

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 six-parameter mutating tool with no annotations, the description covers arguments, defaults, skip logic, and return contents, and the output schema absorbs return-value detail. It is nearly complete; the remaining gap is document-state context (that this rewrites line times and how that interacts with undo/history siblings).

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% and the schema exposes only bare types, so the description must compensate — and it does, defining every one of the six arguments plus their defaults (selection, which, mode, forward_only, max_distance_ms, doc_id) in the Args block. Enum-like values (“both”/“start”/“end”, “nearest”/“previous”/“next”) are enumerated in prose.

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 first sentence states a specific verb and resource: snap line times to keyframes drawn from ``workspace.keyframes``. That distinguishes it from siblings like ass_snap_to_frames, ass_load_keyframes, and ass_fix_timing, and an agent can select it 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?

The description implies usage by noting the keyframes must already be loaded in ``workspace.keyframes`` and gives in-parameter rules (defaults, the forward_only/mode="previous" conflict). It never says when to prefer this over ass_snap_to_frames or what to do if keyframes are absent, so guidance is implied rather than explicit.

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