Read Sandbox File

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

With no annotations, the description carries the full burden. It discloses that paths are workspace-relative and cannot escape the sandbox, and that it reads as text. However, it does not mention behavior for missing files, binary files, or permission errors. It provides some behavioral context but not exhaustive detail.

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 sentences, front-loaded with the core purpose, then the usage context, then the key constraint. Every sentence earns its place; there is no redundancy or fluff.

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 simple read tool with an output schema present, the description covers the essential context: what it reads, when to use it, and a critical limitation. It doesn't explain error handling, but that's minor given the tool's simplicity and the existence of an output schema.

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 coverage is 100%, so both parameters are already described. The description adds the note that paths are workspace-relative, which reinforces the path parameter's meaning, but it does not add new semantics beyond what the schema provides. Baseline 3 applies given high schema coverage.

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 clearly states the tool reads a file from inside the sandbox as text, using a specific verb and resource. It distinguishes itself from sibling tools like write_sandbox_file by focusing on reading, and explicitly notes the sandbox confinement, making its purpose unambiguous.

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 description provides an explicit use case: 'USE THIS to investigate a failure -- read the source, the config, a log'. It does not explicitly mention when not to use it or name alternatives, but the guidance is clear enough for an agent to select it for file inspection. It also clarifies it cannot read the developer's machine, which sets expectations.

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