ui_drag

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

With no annotations, the description carries the burden well: it discloses the press/move/release sequence, that each step runs separately for UI updates, the qtest-vs-event input path distinction, and that it returns actual start/end points. It omits any risk, permission, or focus-change caveats.

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?

Dense and front-loaded: the drag mechanics come first, then start/end targeting, then rationale for per-step execution, then return value. Every sentence carries information, though the start/end enumeration is slightly terse.

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 an 18-parameter, no-annotation, no-output-schema tool, the description covers the essential drag lifecycle, targeting options, and return values. Some timing/modifier parameters remain only in the schema, and there is no note on failure or focus behavior.

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?

At 61% schema coverage, the description adds real value by defining the start (object/ref/query/window x/y) and end (to_x/to_y or offset dx/dy) coordinate schemes, which the schema alone does not explain. Remaining params (steps, hold_ms, settle_ms, modifiers) are left to schema descriptions.

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 (drag) with the exact mechanics: press at start, move in steps, release at end. It is clearly distinguishable from siblings ui_click, ui_hover, and ui_key by describing the multi-step held-button gesture.

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?

Gives a concrete use-case (AutoPosing while dragging a control point) and explains why steps run separately so Cascadeur updates between moves. It lacks explicit when-not-to-use guidance or a direct alternative comparison, keeping it below 5.

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