Move the playhead

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds meaningful behavioral context beyond that: the playhead position affects which keyframe subsequent tools target by default, which is important state-management information.

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 action and followed by the key consequence. Every sentence earns its place and there is no redundant restatement.

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, fully-described three-parameter navigation tool with read-only/idempotent annotations and no output schema, the description covers purpose and the important downstream effect. Minor omissions such as default project behavior are already handled by the schema.

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%, and the schema already explains tick, frame, and project. The description mentions 'keyframe' and 'absolute tick' but adds no syntax, exclusivity, or defaulting details beyond the schema, 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?

The description states a specific verb and resource: 'Move the editor's playhead.' It also clarifies the two positioning modes ('to a keyframe or an absolute tick'), which distinguishes this selection/navigation tool from siblings like keyframe_edit or project_timeline.

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 second sentence gives clear contextual guidance: moving the playhead determines which keyframe later tools edit when no frame is named. It does not explicitly state when not to use the tool or name an alternative, so it falls short of a full when/when-not/alternatives statement.

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