set_playhead

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

No annotations exist, so the description carries the full burden, and it does disclose the important scope constraint that the playhead is moved on the ACTIVE sequence (implying a sequence must be active). It does not state what happens when no sequence is active, whether the move is clamped to sequence bounds, or what is returned.

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?

One short sentence with zero filler, leading with the action and resource. 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?

For a one-parameter, non-destructive positioning tool with no output schema and full schema coverage, the description covers the essentials. The only meaningful omission is the precondition/error behavior around the active sequence.

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 coverage is 100% and the single parameter is already documented as 'Time in seconds', so the description adds nothing about units, fractional frames, or timebase. With one fully documented parameter, the baseline of 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?

States a specific verb ('Set') plus the exact resource ('playhead (CTI) position') and scope ('on the active sequence'). An agent can distinguish it from get_playhead or the go_to_* navigation siblings, though the description never explicitly contrasts itself with those alternatives.

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 explicit when-to-use or when-not guidance. The sibling list contains get_playhead, go_to_in_point, go_to_start, go_to_next_edit, step_forward and others that also move the playhead, yet the description does not say this tool is for arbitrary absolute positioning versus those presets or relative moves.

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