Retrieve the last N lines from a serial port's send history, optionally filtered by start and end timestamps, to review commands already transmitted to a device.
Read the last N lines of the send history.
| Name | Required | Description | Default |
|---|---|---|---|
| port | Yes | ||
| end_time | No | Optional end timestamp | |
| start_time | No | Optional start timestamp | |
| lines_count | No |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It discloses the basic read scope and 'last N lines' limit, but says nothing about whether the port must already be connected, error behavior, permissions, or return format.
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 single sentence is efficient and front-loaded with no filler. However, it is sparse for a tool with four parameters and no annotations.
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?
With no annotations, no output schema, four parameters, and only half the schema documented, the description is missing important context. It does not explain connection prerequisites, time filtering, or what the read returns.
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?
Schema description coverage is only 50%, and the description does not clarify the required port parameter or the start_time/end_time filtering options. It only indirectly explains lines_count via 'last N lines'.
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 states a specific verb and resource: read the last N lines of the send history. The phrase 'send history' distinguishes it from siblings such as read_received_data and read_filtered_data.
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?
It gives no explicit when-to-use guidance, exclusions, or alternatives. A reader can infer it is for inspecting recent sends, but there is no routing guidance against read_received_data, read_filtered_data, or get_buffer_status.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.