Show the timeline

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

The annotations already declare that the tool is read-only and idempotent, so the bar is lower. Because there is no output schema, the description carries the disclosure burden, and it does so by explaining the playback and keyframes structure and by stating that the playback count equals the frame numbers used by the pose and figure tools.

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?

Four short sentences that are front-loaded with the core purpose, and the section definitions come before the filtering hint. Each sentence explains a distinct concept, with no filler or repetition.

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?

There is no output schema, so the description must explain the return shape, and it does so for both sections. It omits the pagination limit semantics and the meaning of the default project, but both are covered in the schema, so the definition is nearly 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?

The schema documents all 4 parameters at 100% coverage, which sets a baseline of 3. The description does add meaning beyond the schema by saying that fromTick and toTick narrow the playback list specifically, which the schema does not state, because the schema describes them only as 'places'.

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 uses the specific verb 'List' with the resource 'timeline of the open project', and it names the two returned sections (playback and keyframes). It never contrasts itself with siblings such as project_describe, keyframe_edit, or keyframe_timing, so an agent has to infer the boundary between them.

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?

It explains one usage lever, 'Give fromTick and toTick to narrow the playback list', and it links frame numbers to the pose and figure tools. It gives no explicit when-to-use or when-not-to-use guidance relative to keyframe_edit, keyframe_timing, or project_describe, so the usage is only implied.

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