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pixoo_display_text

pixoo_display_text
Idempotent

Render styled text onto an LED matrix display, static or animated with scroll, float, or pulse effects, and push it to the device.

Instructions

Render styled text (theme, gradient, shadow, outline, auto-fit) onto the Pixoo display and push it, static or animated with a scroll, float, or pulse effect. Returns the render as an image content block for immediate inspection. The primary tool for text-only display — for layers, icons, widgets, or per-element motion use pixoo_compose_scene. Run pixoo_design_brief with topic "text" first for palette and legibility guidance.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
fontNoFont variant, used as given — text too wide for it overflows rather than switching font: standard (5×7) or compact (3×5), each printable ASCII plus ° ← ↑ → ↓ ▲ ▼ ♥ · …; or numerals (11×18 digits for clocks and readouts), which draws only 0–9, space, and : . - + / % ° ?, so text holding any other character is rejected. Omitted, single-line text tries standard and falls back to compact when standard overflows; multi-line text uses standard.
pushNoPush the rendered frame to the device (default: true).
textYesText to display. String or array of lines.
alignNoMulti-line text: align every line within the widest line, then place that block with position.x. Omit to place each line by position.x on its own.
styleNoText style: palette, shadow, outline, scale.
themeNoNamed scene theme — sets background gradient and default text palette.
effectNoAnimation effect. scroll runs the text across the display once, in up to 40 frames; auto scrolls only when the text is too wide to fit; float (gentle bob) and pulse (breathing brightness) loop over 20 frames. An animated result is pushed as an animation and previewed as a grid of its frames. none or omitted renders one static frame.
positionNoText position on the display.
backgroundNoBackground color or gradient. Overrides theme background when set.
brightnessNoSet device brightness before push (0–100). Failure is a warning, not an error.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
errorNoPresent when the call failed. Absent on success.
framesNoNumber of frames rendered: 1 for static text, 2–40 when an effect animates it.
layoutNoLayout report: every fit decision the renderer made.
noticeNoWarning or informational message about the render or push.
pushedNoTrue when the device acknowledged the push.
deviceStateNoDevice state after the push. Absent when push: false.
outputFilesNoAbsolute paths to saved preview files (PNG, or GIF when an effect animates the text). Present only when PIXOO_OUTPUT_DIR is configured.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed12 schema fields changedv1.3.0
    • changedInput schema / properties / background / anyOf
      Previous value: -[
      -  {
      -    "description": "Solid CSS hex color.",
      -    "type": "string"
      -  },
      -  {
      -    "description": "Gradient background object.",
      -    "properties": {
      -      "gradient": {
      -        "description": "Gradient background specification.",
      -        "properties": {
      -          "from": {
      -            "description": "Gradient start color.",
      -            "type": "string"
      -          },
      -          "to": {
      -            "description": "Gradient end color.",
      -            "type": "string"
      -          },
      -          "type": {
      -            "description": "v = vertical, h = horizontal.",
      -            "enum": [
      -              "v",
      -              "h"
      -            ],
      -            "type": "string"
      -          }
      -        },
      -        "required": [
      -          "type",
      -          "from",
      -          "to"
      -        ],
      -        "type": "object"
      -      }
      -    },
      -    "required": [
      -      "gradient"
      -    ],
      -    "type": "object"
      -  }
      -]New value: +[
      +  {
      +    "description": "Solid CSS hex color.",
      +    "type": "string"
      +  },
      +  {
      +    "additionalProperties": false,
      +    "description": "Gradient background object.",
      +    "properties": {
      +      "gradient": {
      +        "additionalProperties": false,
      +        "description": "Gradient background specification.",
      +        "properties": {
      +          "from": {
      +            "description": "Gradient start color.",
      +            "type": "string"
      +          },
      +          "to": {
      +            "description": "Gradient end color.",
      +            "type": "string"
      +          },
      +          "type": {
      +            "description": "v = vertical, h = horizontal.",
      +            "enum": [
      +              "v",
      +              "h"
      +            ],
      +            "type": "string"
      +          }
      +        },
      +        "required": [
      +          "type",
      +          "from",
      +          "to"
      +        ],
      +        "type": "object"
      +      }
      +    },
      +    "required": [
      +      "gradient"
      +    ],
      +    "type": "object"
      +  }
      +]
    • changedInput schema / properties / font / description
      Previous value: -"Font variant: standard (5×7) or compact (3×5), used as given — text too wide for it overflows rather than switching font. Omitted, single-line text tries standard and falls back to compact when standard overflows; multi-line text uses standard."New value: +"Font variant, used as given — text too wide for it overflows rather than switching font: standard (5×7) or compact (3×5), each printable ASCII plus ° ← ↑ → ↓ ▲ ▼ ♥ · …; or numerals (11×18 digits for clocks and readouts), which draws only 0–9, space, and : . - + / % ° ?, so text holding any other character is rejected. Omitted, single-line text tries standard and falls back to compact when standard overflows; multi-line text uses standard."
    • changedInput schema / properties / font / enum
      Previous value: -[
      -  "standard",
      -  "compact"
      -]New value: +[
      +  "standard",
      +  "compact",
      +  "numerals"
      +]
    • addedInput schema / properties / position / additionalProperties
      Added value: +false
    • addedInput schema / properties / style / additionalProperties
      Added value: +false
    • changedInput schema / properties / style / properties / palette / anyOf
      Previous value: -[
      -  {
      -    "description": "Named built-in color palette for the vertical ramp.",
      -    "enum": [
      -      "ember",
      -      "ice",
      -      "neon",
      -      "fire",
      -      "lavender",
      -      "claude",
      -      "mono"
      -    ],
      -    "type": "string"
      -  },
      -  {
      -    "description": "Custom gradient stop: specify top and bottom colors directly.",
      -    "properties": {
      -      "from": {
      -        "description": "Gradient start color (top).",
      -        "type": "string"
      -      },
      -      "to": {
      -        "description": "Gradient end color (bottom).",
      -        "type": "string"
      -      }
      -    },
      -    "required": [
      -      "from",
      -      "to"
      -    ],
      -    "type": "object"
      -  }
      -]New value: +[
      +  {
      +    "description": "Named built-in color palette for the vertical ramp.",
      +    "enum": [
      +      "ember",
      +      "ice",
      +      "neon",
      +      "fire",
      +      "lavender",
      +      "claude",
      +      "mono"
      +    ],
      +    "type": "string"
      +  },
      +  {
      +    "additionalProperties": false,
      +    "description": "Custom gradient stop: specify top and bottom colors directly.",
      +    "properties": {
      +      "from": {
      +        "description": "Gradient start color (top).",
      +        "type": "string"
      +      },
      +      "to": {
      +        "description": "Gradient end color (bottom).",
      +        "type": "string"
      +      }
      +    },
      +    "required": [
      +      "from",
      +      "to"
      +    ],
      +    "type": "object"
      +  }
      +]
    • changedOutput schema / properties / layout / items / properties / action / description
      Previous value: -"Overflow action taken by the renderer."New value: +"What the renderer did about the width: shrunk-to-compact when single-line text fits only in the compact font; scrolling when the returned frames scroll (effect scroll, or auto on text too wide to fit); none otherwise. A line too wide for the panel that does not scroll reports none with fits false, drawn from x 0 and cut at the right edge."
    • changedOutput schema / properties / layout / items / properties / action / enum
      Previous value: -[
      -  "none",
      -  "shrunk-to-compact",
      -  "scrolling",
      -  "wrapped",
      -  "truncated",
      -  "clipped"
      -]New value: +[
      +  "none",
      +  "shrunk-to-compact",
      +  "scrolling"
      +]
    • removedOutput schema / properties / layout / items / properties / element / anyOf
      Removed value: -[
      -  {
      -    "description": "Zero-based index of the element in the input array.",
      -    "type": "number"
      -  },
      -  {
      -    "const": "background",
      -    "type": "string"
      -  }
      -]
    • changedOutput schema / properties / layout / items / properties / element / description
      Previous value: -"Element index or \"background\" for the background layer."New value: +"Zero-based line index: 0 for single-line text, the line position for an array."
    • addedOutput schema / properties / layout / items / properties / element / type
      Added value: +"number"
    • changedOutput schema / properties / layout / items / properties / font / enum
      Previous value: -[
      -  "standard",
      -  "compact"
      -]New value: +[
      +  "standard",
      +  "compact",
      +  "numerals"
      +]
  2. Changed8 schema fields changedv1.2.0
    • changedInput schema / properties / align / description
      Previous value: -"Multi-line text alignment (default: center)."New value: +"Multi-line text: align every line within the widest line, then place that block with position.x. Omit to place each line by position.x on its own."
    • changedInput schema / properties / effect / description
      Previous value: -"Animation effect. auto = scroll only when text overflows. Produces a multi-frame result."New value: +"Animation effect. scroll runs the text across the display once, in up to 40 frames; auto scrolls only when the text is too wide to fit; float (gentle bob) and pulse (breathing brightness) loop over 20 frames. An animated result is pushed as an animation and previewed as a grid of its frames. none or omitted renders one static frame."
    • changedInput schema / properties / font / description
      Previous value: -"Font variant: standard (5×7) or compact (3×5). Auto-fit will choose if omitted."New value: +"Font variant: standard (5×7) or compact (3×5), used as given — text too wide for it overflows rather than switching font. Omitted, single-line text tries standard and falls back to compact when standard overflows; multi-line text uses standard."
    • changedOutput schema / anyOf
      Previous value: -[
      -  {
      -    "not": {
      -      "required": [
      -        "error"
      -      ]
      -    },
      -    "required": [
      -      "pushed",
      -      "layout"
      -    ]
      -  },
      -  {
      -    "required": [
      -      "error"
      -    ]
      -  }
      -]New value: +[
      +  {
      +    "not": {
      +      "required": [
      +        "error"
      +      ]
      +    },
      +    "required": [
      +      "pushed",
      +      "frames",
      +      "layout"
      +    ]
      +  },
      +  {
      +    "required": [
      +      "error"
      +    ]
      +  }
      +]
    • changedOutput schema / properties / error / properties / data / properties / reason / description
      Previous value: -"Machine-readable failure mode. Declared by this tool: `device_unreachable`: Device is not reachable over the network. `device_rejected`: Device firmware returned a non-zero error code. `no_device_configured`: PIXOO_IP is not set. `invalid_color`: A color value could not be resolved. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `device_unreachable`: Device is not reachable over the network. `device_http_error`: The device answered with a non-2xx HTTP status (retryable for 408, 429, 500, and 502–504). `device_rejected`: Device firmware returned a non-zero error code. `no_device_configured`: PIXOO_IP is not set. `invalid_color`: A color value could not be resolved. Other values are possible when a failure originates below the handler."
    • changedOutput schema / properties / error / properties / data / properties / reason / examples
      Previous value: -[
      -  "device_unreachable",
      -  "device_rejected",
      -  "no_device_configured",
      -  "invalid_color"
      -]New value: +[
      +  "device_unreachable",
      +  "device_http_error",
      +  "device_rejected",
      +  "no_device_configured",
      +  "invalid_color"
      +]
    • addedOutput schema / properties / frames
      Added value: +{
      +  "description": "Number of frames rendered: 1 for static text, 2–40 when an effect animates it.",
      +  "type": "number"
      +}
    • changedOutput schema / properties / outputFiles / description
      Previous value: -"Absolute paths to saved PNG preview files. Present only when PIXOO_OUTPUT_DIR is configured."New value: +"Absolute paths to saved preview files (PNG, or GIF when an effect animates the text). Present only when PIXOO_OUTPUT_DIR is configured."
  3. Changed8 schema fields changedv1.1.1
    • changedInput schema / $schema
      Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"
    • addedInput schema / additionalProperties
      Added value: +false
    • changedOutput schema / $schema
      Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"
    • addedOutput schema / anyOf
      Added value: +[
      +  {
      +    "not": {
      +      "required": [
      +        "error"
      +      ]
      +    },
      +    "required": [
      +      "pushed",
      +      "layout"
      +    ]
      +  },
      +  {
      +    "required": [
      +      "error"
      +    ]
      +  }
      +]
    • addedOutput schema / properties / error
      Added value: +{
      +  "additionalProperties": {},
      +  "description": "Present when the call failed. Absent on success.",
      +  "properties": {
      +    "code": {
      +      "description": "JSON-RPC error code for this failure.",
      +      "maximum": 9007199254740991,
      +      "minimum": -9007199254740991,
      +      "type": "integer"
      +    },
      +    "data": {
      +      "additionalProperties": {},
      +      "properties": {
      +        "reason": {
      +          "description": "Machine-readable failure mode. Declared by this tool: `device_unreachable`: Device is not reachable over the network. `device_rejected`: Device firmware returned a non-zero error code. `no_device_configured`: PIXOO_IP is not set. `invalid_color`: A color value could not be resolved. Other values are possible when a failure originates below the handler.",
      +          "examples": [
      +            "device_unreachable",
      +            "device_rejected",
      +            "no_device_configured",
      +            "invalid_color"
      +          ],
      +          "type": "string"
      +        },
      +        "recovery": {
      +          "additionalProperties": {},
      +          "description": "Actionable next step for the caller.",
      +          "properties": {
      +            "hint": {
      +              "type": "string"
      +            }
      +          },
      +          "required": [
      +            "hint"
      +          ],
      +          "type": "object"
      +        },
      +        "retryable": {
      +          "description": "Whether retrying may succeed.",
      +          "type": "boolean"
      +        }
      +      },
      +      "type": "object"
      +    },
      +    "message": {
      +      "description": "Human-readable description of what went wrong.",
      +      "type": "string"
      +    }
      +  },
      +  "required": [
      +    "code",
      +    "message"
      +  ],
      +  "type": "object"
      +}
    • removedOutput schema / properties / previewData
      Removed value: -{
      -  "description": "Base64-encoded PNG preview of the rendered frame (8× upscaled, 512px).",
      -  "type": "string"
      -}
    • removedOutput schema / properties / previewMimeType
      Removed value: -{
      -  "description": "MIME type of the preview image.",
      -  "enum": [
      -    "image/png"
      -  ],
      -  "type": "string"
      -}
    • removedOutput schema / required
      Removed value: -[
      -  "pushed",
      -  "layout"
      -]
  4. First observedv1.0.0

TDQS

A4.5/5.0
Behavior4/5

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

Annotations already declare idempotentHint and destructiveHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: the return is an image content block for inspection, and an animated result is pushed as an animation and previewed as a grid of frames. It does not discuss failure modes or device-auth requirements, keeping it short of a 5.

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?

Three tightly packed sentences, each earning its place: capability, return/push behavior, sibling routing plus prerequisite. Front-loaded with the core action and no filler.

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?

With an output schema present, the description needn't explain return values, yet it still notes the image-block preview. Annotations, a 100%-covered schema, and sibling routing together leave nothing an agent needs to call this correctly missing.

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

Parameters3/5

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

Schema description coverage is 100% and the parameters are richly documented in the schema (font fallback rules, effect frame counts, palette stops, position semantics). The description only gestures at the feature set ('theme, gradient, shadow, outline, auto-fit') without adding syntax or defaults beyond the schema, so baseline 3 is appropriate.

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

Purpose5/5

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

The description opens with a specific verb+resource ('Render styled text ... onto the Pixoo display and push it') and enumerates the styling and motion capabilities, so an agent immediately knows this is the text-rendering tool rather than a scene composer or overlay tool.

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

Usage Guidelines5/5

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

It explicitly routes away from siblings ('for layers, icons, widgets, or per-element motion use pixoo_compose_scene') and gives a prerequisite ('Run pixoo_design_brief with topic "text" first for palette and legibility guidance'). The only minor omission is distinguishing from pixoo_overlay_text, but the primary routing is explicit.

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