Retrieve a bounded page of raw stdout or stderr log bytes from a session using a handle; returns base64-encoded data for inspecting or processing command output.
Read a bounded raw byte page from an opt-in session log; base64 encoded. Handles are process-local and expire after one hour.
| Name | Required | Description | Default |
|---|---|---|---|
| handle | Yes | ||
| length | Yes | ||
| offset | Yes | ||
| stream | Yes |
Changes observed during successful MCP inspections.
v0.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden and discloses several useful traits: the read is bounded, the data is base64 encoded, handles are process-local, and handles expire after one hour. It still omits error behavior, pagination/end-of-stream semantics, and permission requirements, but the core behavioral profile is strong for an unannotated tool.
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 description is two tight sentences with no waste. The core purpose and the most important constraint, handle expiration, are front-loaded.
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 four-parameter read tool with no annotations and no output schema, the description covers encoding and handle lifetime but leaves out return shape, how to detect the end of the log, and how this differs from read_execution_output. It is minimally adequate but has clear gaps.
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 0%, so the description should compensate for the four undocumented parameters. It implies that offset and length define a byte page and notes handle expiration, but it does not explain the handle format, the stdout/stderr enum, or the maximum page size beyond what the schema already structurally enforces.
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: reading a bounded raw byte page from an opt-in session log. It is clear what the tool does, but it does not explicitly distinguish itself from sibling tools such as read_execution_output or delete_output_log.
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?
The phrase 'opt-in session log' implies that logging must be enabled, but there is no explicit guidance on when to choose this tool over read_execution_output or how to handle related operations. No alternatives or exclusions are named.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.