Set Playhead Position

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

Annotations already declare the mutation/safety profile (readOnlyHint=false, destructiveHint=false), lowering the bar. The description adds two genuinely useful behaviors beyond that: the value is clamped to the sequence end, and the stored position is read back for verification. It does not state the active-sequence requirement or whether the change is undoable.

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?

A single front-loaded sentence with three tightly ordered clauses (set, clamp, read back) and zero filler. Nothing is wasted or buried.

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?

An output schema exists, so return values need no explanation, and the clamp/readback behavior is covered. The only gap is the unstated prerequisite of an active sequence and the relationship to navigate_playhead, which for a one-parameter tool is a minor omission.

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 single parameter already documents the seconds range, so the schema carries the load. The description only reinforces the clamping bound with no additional syntax or format detail.

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?

States a specific verb+resource ('Set the playhead (CTI) position') and adds the distinguishing CTI synonym. However, it does not differentiate itself from close siblings like navigate_playhead or get_playhead_position, which an agent must choose between.

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?

There is no when-to-use guidance, no prerequisite (an active sequence must exist), and no reference to the alternative navigate_playhead tool that also moves the playhead. The agent is left to infer selection from names alone.

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