Execute a task with Codex

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

With no annotations, the description must convey behavior. It mentions returning sessionId for later feedback and includes sandbox policy parameter, but does not explain execution risks, authorization, or rate limits. Some transparency but insufficient for a tool with destructive potential.

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 sentences, front-loaded with purpose and return values. Efficient but could be sharper; the reminder about sessionId could be moved to parameter description.

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, no output schema, and sibling tools, the description covers core function but omits when-to-use details, parameter interactions, and sandbox implications. Adequate but leaves 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 coverage is 100% (all 6 parameters described), so description adds no extra meaning. Baseline of 3 applies as description does not compensate with additional context.

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?

Description clearly states the tool starts a new Codex session, executes a plan/task in a workspace, and lists key outputs (sessionId, agent message, file changes, commands). This distinguishes it from siblings like codex_continue (which likely continues an existing session).

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 implies use when initiating a new task but does not explicitly compare with siblings or state when not to use. It lacks guidance on selecting this over codex_continue or codex_review.

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