Picodev Lab

Read a capture

read_capture

Read-only

State of a capture (recording, ready, failed) and its kind (logic, analog). Once ready, the measures per pin and, for a logic capture, the edges [t_us, pin, v], 2000 from offset; for an analog one, rate_hz and the samples, rows [mv_1, ...] in the order of pins (row k at k / rate_hz), 2000 rows from offset. next: the following offset, or null. t0_ms: the first sample on the session's clock (ms since the simulation's launch, or since the start of the turn on a real bench), null when unknown; t_us and rows count from the capture's start. format="png": the same without edges or samples, plus a chart of the signals as an image (from_ms and to_ms, from the capture's start, to zoom; 4 per minute).

Input Schema

Name	Required	Default
`to_ms`	No
`format`	No	json
`offset`	No
`capture`	Yes
`from_ms`	No
`session`	No
`agent_token`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedOct 23, 2026
- addedInput schema / properties / agent_token / anyOf
```
Added value: +[
+  {
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]
```
- addedInput schema / properties / agent_token / default
```
Added value: +null
```
- removedInput schema / properties / agent_token / type
```
Removed value: -"string"
```
- addedInput schema / properties / session / anyOf
```
Added value: +[
+  {
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]
```
- addedInput schema / properties / session / default
```
Added value: +null
```
- removedInput schema / properties / session / type
```
Removed value: -"string"
```
- changedInput schema / required
```
Previous value: -[
-  "session",
-  "agent_token",
-  "capture"
-]New value: +[
+  "capture"
+]
```
First observedOct 21, 2026

TDQS

A3.8/5.0

Behavior4/5

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

Annotations already cover read-only/non-destructive/closed-world, and the description goes well beyond them: pagination of 2000 items from offset, the null-terminated `next` cursor, t0_ms clock semantics (simulation launch vs. turn start on a real bench), state-dependent payload availability, and a real rate limit (4 chart requests per minute). It stops short of saying what happens if you read a capture that is still recording (error vs. state-only response).

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?

One dense block with no filler sentences; state/kind is front-loaded before the conditional payload descriptions. Every clause carries information (units, array layouts, cursor semantics), though the run-on grammar makes it hard to parse on first read.

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?

With no output schema, the description fully carries the return contract: field names, units (t_us, mv, rate_hz), row ordering relative to pins, and cursor behavior are all spelled out. The remaining gap is error/lifecycle behavior when the capture is not ready and the meaning of the session/agent_token parameters.

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 0%, so the description carries the burden: it explains offset (2000 items per page), format="png", and from_ms/to_ms (measured from capture start, used to zoom). It says nothing about `capture`, `session`, or `agent_token`, leaving three of seven parameters completely unexplained in both schema and prose.

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 the resource precisely (a capture) and enumerates what it returns: state (recording/ready/failed), kind (logic/analog), per-pin measures, and either edges or samples. It is specific enough to distinguish this as the read/fetch companion to capture_logic/capture_analog, but it never states that distinction explicitly or contrasts with decode_capture.

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?

Usage is only implied: the polling loop is hinted at by 'Once ready...' plus 'next: the following offset, or null', and format="png" is offered as a chart alternative to raw data. There is no explicit 'use this when...' guidance and no sibling named as an alternative for any case.

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

All Picodev Lab tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Read a capture

Input Schema

Schema Changelog

TDQS

Glama MCP Gateway

Resources