Drag

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

Annotations indicate readOnlyHint=false and destructiveHint=false, but the description adds the auth requirement 'Requires Accessibility permission' and reveals the behavior of 'interpolated intermediate points,' which is not present in the annotations. This provides meaningful context beyond the structured fields.

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?

The description is a single clear sentence of 19 words with no filler. It front-loads the core action and includes the essential permission note. Every word earns its place.

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 tool with 7 parameters and no output schema, the description covers the core action and the required permission. It defines the purpose of the required coordinate parameters via the 'point' language, and optional parameters have schema descriptions. While it could mention coordinate units or synchronous execution, these are not critical for basic understanding of a drag operation.

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 low (43%), with fromX/fromY/toX/toY lacking descriptions. The description partially compensates by framing these as 'one point' and 'another,' clarifying they are start/end coordinates. However, it does not explain units (pixels) or coordinate system, and optional parameters rely on schema descriptions. Still, it adds some meaning beyond the bare schema.

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 clearly states the action: 'Press the mouse button at one point, drag through interpolated intermediate points, and release at another.' This specific verb+resource (drag) distinguishes it from sibling tools like input_click and input_move_mouse.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention exclusions, alternatives, or typical use cases beyond the basic action. The only additional note is the Accessibility permission requirement, which is a prerequisite, not usage guidance.

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