read_displayReads the Face Display module’s mode, text lines, frame and FPS stats, byte count, and 128×64 GDDRAM pixels as ASCII art so you can inspect what the display is showing.
Read back what the Face Display module is showing: mode (face/text), text lines, module stats (frames, fps, bytes) and the actual 128×64 pixels from the module's GDDRAM as ASCII art (█▀▄, 2 pixel rows per line).
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds meaningful behavioral detail beyond that: the exact payload contents and the rendering convention for the pixel dump (█▀▄, 2 pixel rows per line). It does not warn that a 128×64 dump is ~32 lines of 128 characters, which matters for context budget.
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?
A single dense sentence, front-loaded with the verb and resource, then the return contents. Nothing redundant given annnotations already carry safety hints.
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?
No output schema exists, so the description must carry the return-value burden, and it largely does by enumerating mode, text, stats and pixel rendering. The gap is the shape/magnitude of the ASCII art output and whether stats are cumulative or per-frame, which an agent budgeting context would want to know.
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?
There are zero parameters, so the baseline is 4 — there is nothing for the description to disambiguate. It correctly implies the tool takes no arguments by framing it as pure read-back.
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?
Specific verb (read back) plus specific resource (the Face Display module's current state), and it enumerates exactly what is returned: mode, text lines, stats, and GDDRAM pixels. This clearly separates it from the write-side siblings set_display / draw_display / display_text.
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?
Usage is only implied — an agent can infer this is the read-back/diagnostic counterpart to the display-writing tools. There is no explicit statement of when to call it (e.g., after set_display to verify) and no naming of alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.