Run Codex CLI

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

With no annotations, the description discloses key behaviors: local installation requirement, non-interactive mode, sandbox, default read-only, and return structure (final message plus summaries). Warns about enabling writes via workspace_write.

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?

Three succinct sentences, each providing distinct value: purpose, usage guideline, and return description. No redundancy or unnecessary detail.

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?

Given 6 parameters and no output schema, the description covers the tool's purpose, key behavioral constraints, and output summary. Could briefly elaborate on 'events' output mode for full completeness.

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 has 100% parameter description coverage, so baseline is 3. The description adds context for the mode parameter (when to use workspace_write) and hints at return format, but does not significantly enhance understanding of other parameters.

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?

Clearly identifies the tool as running Codex CLI non-interactively in a sandbox, with a default read-only mode. However, it does not explicitly differentiate from sibling tools like opencode_run, limiting clarity slightly.

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?

Provides explicit guidance: 'Use workspace_write only when writes are enabled server-side.' This helps the agent decide when to use each mode. Missing contrast with opencode_run or other alternatives.

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