Agent Cam MCP Tool

read_events

Retrieve timestamped lines from serial, log-file, or MQTT sources; optionally block until specific text appears or timeout.

Instructions

Read timestamped lines from an active event adapter (serial, log file, MQTT). Can block until specific text appears or until timeout.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "source": "<source>"
    },
    "name": "read_events"
  }
}

Input Schema

Name	Required	Description
`lines`	No	Max lines to return
`source`	Yes	Adapter source name (e.g. 'serial:COM1', 'logfile')
`timeout_s`	No	Timeout in seconds to wait for until_text
`until_text`	No	Optional text to wait for
`last_seconds`	No	Time window in seconds

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 4, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations, the description carries the full behavioral burden, and it does disclose the single most important trait: the call can block until matching text appears or until timeout. It does not state whether reading consumes/advances the buffer, what happens for an unknown source, or any error/permission behavior, leaving meaningful gaps for a snapshot-less tool.

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 tightly written sentences with the resource and source types front-loaded, followed by the blocking behavior. No filler and nothing repeated from the schema.

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

Completeness3/5

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

For a 5-parameter tool with no output schema and no annotations, the description covers the source domain and blocking semantics but omits return shape (line format, ordering), buffer-consumption behavior, and failure modes for an invalid source. Adequate to make the call, insufficient to predict the result.

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 baseline is 3. The description adds one relational detail the schema does not convey on its own — that until_text pairs with a timeout — but lines, last_seconds, and source semantics are left entirely to the schema.

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?

Names a specific verb and resource ('Read timestamped lines from an active event adapter') and enumerates concrete source types (serial, log file, MQTT), so the agent knows exactly what the tool operates on. It does not, however, differentiate itself from the sibling read_text, which an agent may reasonably confuse with this tool.

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 source examples and the blocking capability hint at when this applies, but there is no explicit when-to-use statement, no mention of prerequisites (adapter must be active), and no routing away from read_text. The bar for 4 (clear context, no exclusions) is not met.

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