Navigate Playhead

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

Beyond the annotations, the description discloses a key behavioral guarantee: it never changes clips. It also reveals the combined behavior of moving and then reading back the resulting position. This is consistent with readOnlyHint=false because moving the playhead is a state change; there is no contradiction.

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 with no filler. The first sentence front-loads the action, destinations, and read-back result, while the second adds the important non-destructive clarification.

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 moderately complex tool with a complete input schema and an output schema, the description supplies the necessary active-sequence scope and the safety guarantee. It does not discuss edge cases like missing active sequence or boundary behavior, but those are not critical for correct invocation.

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%, so the schema already documents all four parameters well. The description provides high-level context for the action enum and the frames parameter ('step a number of frames') but adds little semantic detail over the schema for track_type or track_index.

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 a specific verb and resource ('Move the active-sequence playhead') and enumerates concrete destinations: start, end, in/out points, work-area bounds, edits, markers, and frame steps. It also adds the read-back behavior, which clearly separates it from simple set-position and get-position siblings.

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 phrase 'Navigation only; it never changes clips' gives a clear safety and usage context: this is the non-destructive playhead-movement tool rather than an editing operation. However, it does not explicitly name alternative tools like set_playhead_position or get_playhead_position, so exclusions remain partly implied.

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