Fetch truncated output from a background process by specifying a byte offset. Use process_id to target the process and offset to start reading.
Read output from a specific byte offset. Used for truncated output.
| Name | Required | Description | Default |
|---|---|---|---|
| offset | No | Byte offset to start reading from (default: 0) | |
| process_id | No | Background process_id |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden, and it does disclose the offset-based read model (output is addressable and re-readable rather than consumed). It omits whether repeated reads are safe, what happens when process_id is omitted, and whether output is buffered or lost.
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?
Two short sentences, no filler, and the core mechanic (byte offset) is front-loaded ahead of the use case. Nothing could be removed without losing signal.
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?
For a 2-parameter tool with no output schema or annotations, the description should clarify how this fits the process-output workflow (start_process → poll_output → read_output) and what a truncated read returns. That relationship, which is the main thing an agent needs, is absent.
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 100%, so both parameters are already documented in the schema, and the description only echoes 'byte offset' without adding format or default semantics. The 3 baseline applies when the schema does the heavy lifting.
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?
States a specific verb and resource ('Read output') plus its signature constraint ('from a specific byte offset'), which is more precise than a generic read. However it never distinguishes itself from the sibling poll_output, which an agent will see in the same list and must disambiguate by inference.
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?
'Used for truncated output' gives an implied trigger condition, so the when is partially conveyed. It does not state when NOT to use it or name the alternative (poll_output) for live/new output, leaving the choice between the two output tools to guesswork.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.