Read a file produced by Codex

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

No annotations are provided, so the description carries the full burden. It adds useful behavior beyond the schema by stating that images are returned as image content and everything else as text. However, it does not disclose error handling, permission requirements, or what happens with nonexistent files—gaps that would matter for a read 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?

Two short sentences with no filler. The purpose is front-loaded, and the output-type behavior is stated succinctly. Every sentence earns its place.

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 tool with two parameters and full schema documentation, the description covers the key context: what file to read and how the content will be returned. It lacks explicit error handling and edge-case details, but does not need to explain return values since there is no output schema and the description handles output type.

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. The description adds no parameter-specific guidance, but it does not need to because the schema fully covers path and max_bytes semantics. This matches the baseline for full 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 states a specific verb ('Read'), a resource ('one file from a Codex workspace'), and the purpose ('artifacts that were too large to inline'). It also differentiates from siblings by clarifying that it reads files, while codex_generate_image generates images and codex_run likely executes tasks.

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 gives the clear context 'for artifacts that were too large to inline,' which tells an agent when to reach for this tool. It does not explicitly name alternative tools or state exclusions, but the use case is specific enough to strongly infer when it applies.

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