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Robot Actions — Remote Device Control

iOS pinch

ios_pinch

Two-finger pinch-to-zoom centred at (x,y) on an iOS device. scale > 1 zooms IN (fingers spread), scale < 1 zooms OUT (fingers converge); ~2 doubles, ~0.5 halves. Both fingers ride a vertical axis through the centre and are auto-clamped on-screen. Use on Maps, Photos, Safari, camera. Coordinates are screen points. Works without an automation session when the direct input path is available; falls back to one otherwise (see input).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
xYesPinch centre X (screen points)
yYesPinch centre Y (screen points)
normNoIf true, x/y (and path points) are 0..1 FRACTIONS of the screen — pass `pixelInScreenshot ÷ screenshotSize` directly (scale-free, matches the frontend, avoids point-guessing). Default false = iOS screen points.
udidYesiOS device UDID
inputNoInput path. 'auto' (default) tries the direct input path first — the one that needs no automation session — and falls back to the session only when the direct path is not usable right now (the response says which one ran). On a device set to direct-input-only, an unusable direct path is reported as an error instead of silently switching to the session. 'hid' forces the direct path with no fallback, reporting 'no HID available' on iOS 17.x or with no tunnel. 'session' forces the automation session even when the direct path would have worked.
scaleYesEnd/start finger-separation ratio: >1 zoom in, <1 zoom out (0.2–5)
durationMsNoGesture duration in ms (default: 250)

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • changedInput schema / properties / input / description
      Previous value: -"Input path. 'auto' (default) tries the direct input path first — the one that needs no automation session — and falls back to the session only when the direct path is not usable right now (the response says which one ran). 'hid' forces the direct path with no fallback, reporting 'no HID available' on iOS 17.x or with no tunnel. 'session' forces the automation session even when the direct path would have worked."New value: +"Input path. 'auto' (default) tries the direct input path first — the one that needs no automation session — and falls back to the session only when the direct path is not usable right now (the response says which one ran). On a device set to direct-input-only, an unusable direct path is reported as an error instead of silently switching to the session. 'hid' forces the direct path with no fallback, reporting 'no HID available' on iOS 17.x or with no tunnel. 'session' forces the automation session even when the direct path would have worked."
  2. Changed2 schema fields changed
    • changedInput schema / properties / input / description
      Previous value: -"Input path. 'auto' (default) drives the gesture through the automation session. 'hid' drives it through the direct input path instead, which needs no automation session — it reports 'no HID available' on iOS 17.x or with no tunnel."New value: +"Input path. 'auto' (default) tries the direct input path first — the one that needs no automation session — and falls back to the session only when the direct path is not usable right now (the response says which one ran). 'hid' forces the direct path with no fallback, reporting 'no HID available' on iOS 17.x or with no tunnel. 'session' forces the automation session even when the direct path would have worked."
    • changedInput schema / properties / input / enum
      Previous value: -[
      -  "auto",
      -  "hid"
      -]New value: +[
      +  "auto",
      +  "hid",
      +  "session"
      +]
  3. Changed2 schema fields changed
    • addedInput schema / properties / input
      Added value: +{
      +  "description": "Input path. 'auto' (default) drives the gesture through the automation session. 'hid' drives it through the direct input path instead, which needs no automation session — it reports 'no HID available' on iOS 17.x or with no tunnel.",
      +  "enum": [
      +    "auto",
      +    "hid"
      +  ],
      +  "type": "string"
      +}
    • addedInput schema / properties / norm
      Added value: +{
      +  "description": "If true, x/y (and path points) are 0..1 FRACTIONS of the screen — pass `pixelInScreenshot ÷ screenshotSize` directly (scale-free, matches the frontend, avoids point-guessing). Default false = iOS screen points.",
      +  "type": "boolean"
      +}
  4. First observed

TDQS

A4.4/5.0
Behavior5/5

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

Annotations only cover the safety profile (readOnly=false, destructive=false), leaving the description to carry real behavior. It does: fingers ride a vertical axis, are auto-clamped on-screen, the direct input path is tried first with a documented fallback, direct-input-only devices error rather than silently switching, and 'the response says which one ran.' That is substantial disclosure beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the operation and coordinate centre, then scale semantics, then usage contexts, then the input-path caveat. Five dense sentences with no filler; each clause carries information an agent needs.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, so the description must cover behavior, and it does — including that the response reports which input path ran. With schema descriptions covering all 7 parameters, nothing needed for a correct call is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description nevertheless adds meaning beyond the schema by giving concrete scale semantics ('~2 doubles, ~0.5 halves', 'fingers spread/converge') and restating that coordinates are screen points, which reinforces the norm/points distinction.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource+scope: 'Two-finger pinch-to-zoom centred at (x,y) on an iOS device.' An agent can distinguish it from gesture siblings like ios_two_finger_swipe or ios_gesture_path by the pinch-specific semantics. It never explicitly names a sibling alternative, so it stops short of the top band.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete application contexts ('Use on Maps, Photos, Safari, camera') so the agent knows where the gesture is appropriate, and the input-path sentence explains the session/no-session conditions. There is no explicit when-not-to-use guidance or named alternative gesture.

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

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