set_join_mode_tool

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

No annotations are provided, so the description carries the full burden, and it does disclose real behavior: it only changes the join mode, leaves existing fades untouched, and a crossfade with no fades degrades to a plain join, with join_crossfade_blocked explaining why. Missing permission/undo semantics, but the key side-effect quirks are surfaced well.

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?

Front-loads the core action and accepted values in the first line, then adds the behavioral caveat. No filler, though the opaque 'TOOL_TIMEBASE: na' fragment adds little for an agent.

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 not be explained, and the description still points at the useful join_crossfade_blocked field. For a mutation tool with no annotations and 0% schema coverage, the only real gap is the undocumented project_path.

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 0%, so the description must compensate. It does document the join_in_mode domain (fade | crossfade | cut) and implies clip_id via 'one clip', but the optional project_path is documented nowhere, and there is no format guidance for clip_id.

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 join_in_mode on one clip') and enumerates the three accepted values (fade | crossfade | cut). Names a sibling alternative, set_clip_join_tool, which lets an agent distinguish it from adjacent join tools, though it doesn't spell out how the two differ.

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?

'Prefer ``set_clip_join_tool``' is an explicit routing directive toward an alternative. What is missing is the condition that should select this tool over that one; the agent must infer it from the mode-only scoping note.

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