Render a 320x240 PNG mirror of the current UI tree for visual observation without reading the physical LCD, aiding in app debugging and remote monitoring.
Machine-specific (cyd). Observation, L0. Render a lightweight logical 320x240 PNG mirror from the retained UI tree. This is not an LCD pixel readback.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full behavioral disclosure burden. It discloses that the output is a logical, lightweight PNG derived from the retained UI tree rather than actual pixel data, and 'Observation' implies read-only behavior. This is meaningful context, though it does not elaborate on error conditions or environmental prerequisites.
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 extremely concise: two short sentences plus a terse classification fragment. Every element earns its place by adding machine scope, observation level, output type, and a key caveat. Nothing is wasted.
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 no-parameter observation tool with no output schema, the description covers the essential facts: what it renders, the resolution, the source data, and the important caveat that it is not pixel-accurate. It could be slightly more explicit about the exact return value format, but 'PNG mirror' is sufficiently clear.
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?
The tool has zero parameters, and the input schema is empty, so the baseline is 4. The description does not need to add parameter semantics because there are none to document.
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 uses a specific verb and resource: 'Render a lightweight logical 320x240 PNG mirror from the retained UI tree.' It clearly distinguishes itself from pixel-level capture by stating 'This is not an LCD pixel readback,' which separates it from related tools like cyd_ui_tree.
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 phrase 'Observation, L0' gives clear context for when the tool is appropriate, and the explicit exclusion 'not an LCD pixel readback' helps an agent avoid misuse. It does not name a specific sibling alternative or describe when not to use it beyond that exclusion, so it falls short of full 5-level guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.