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read_screen

Read-onlyIdempotent

Retrieve terminal screen content and parsed agent status from a multiplexer workspace. Use raw mode for full text or parsed-only output for monitoring agents.

Instructions

Read a terminal screen and parsed harness status. Use raw=true for full text or parsed_only=true for monitoring.

Input Schema

TableJSON Schema

Name	Required	Description
`raw`	No	If true, include the full untrimmed terminal content (separators, status-bar art, all lines). Default false returns a compact de-chromed screen_preview instead.
`lines`	No	Number of lines to read
`surface`	No	Target surface ref
`workspace`	No	Target workspace ref
`scrollback`	No	Include scrollback buffer
`surface_id`	No	Alias for `surface`, as emitted by list_agents/spawn_agent.
`parsed_only`	No	If true, return only parsed fields (omit screen content). Best for agent monitoring.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`ok`	Yes
`parsed`	No
`surface`	No
`retry_count`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed5 schema fields changedv0.4.88Sep 26, 2026

addedInput schema / properties / parsed_only

Added value: +{
+  "default": false,
+  "description": "If true, return only parsed fields (omit screen content). Best for agent monitoring.",
+  "type": "boolean"
+}

addedInput schema / properties / raw

Added value: +{
+  "default": false,
+  "description": "If true, include the full untrimmed terminal content (separators, status-bar art, all lines). Default false returns a compact de-chromed screen_preview instead.",
+  "type": "boolean"
+}

addedInput schema / properties / surface_id

Added value: +{
+  "description": "Alias for `surface`, as emitted by list_agents/spawn_agent.",
+  "type": "string"
+}

removedInput schema / required
```
Removed value: -[
-  "surface"
-]
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": true,
+  "properties": {
+    "ok": {
+      "type": "boolean"
+    },
+    "parsed": {
+      "additionalProperties": {},
+      "type": "object"
+    },
+    "retry_count": {
+      "minimum": 0,
+      "type": "integer"
+    },
+    "surface": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "ok",
+    "retry_count"
+  ],
+  "type": "object"
+}

First observedv0.1.0Mar 21, 2026

TDQS

A3.8/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the tool returns two kinds of content (terminal text and parsed harness status), and the mode selects which one the caller gets, which matters for how an agent consumes the result.

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?

Two short sentences, zero filler. The purpose is front-loaded first, followed immediately by the only mode-selection guidance an agent needs. Every word earns its place.

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

Completeness4/5

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

For a read-only tool with full schema coverage on all 7 parameters, an output schema, and safety annotations covering the behavioral risk, the description is nearly complete. The only minor gap is that it does not describe the shape of the 'parsed harness status' fields, but the output schema presumably covers that, so nothing critical is 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%, so the schema already fully documents all 7 parameters. The description's mention of raw=true and parsed_only=true merely restates the schema's own detailed explanations ('full untrimmed terminal content' vs 'return only parsed fields') without adding new semantic value, matching the baseline of 3.

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?

The description names a specific verb and resource ('Read a terminal screen and parsed harness status'), and the dual-output mention (raw text vs parsed status) distinguishes it from sibling reads like list_surfaces or list_agents. It is clear, though it does not explicitly name any sibling it is not.

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

Usage Guidelines3/5

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

The line 'Use raw=true for full text or parsed_only=true for monitoring' gives explicit context for choosing between the two output modes. However, it provides no when-not-to-use guidance or comparison against sibling tools such as wait_for or list_agents, leaving tool-selection mostly to inference.

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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