Codex Implement

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

With no annotations provided, the description carries the burden of behavioral disclosure. It explicitly warns that the tool modifies the codebase and states that it returns a summary of changes, which are the most important behavioral characteristics for an agent to know.

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 concise: two sentences that cover purpose, a safety warning, and the return type. The WARNING is front-loaded and the most critical information is easy to notice. A little more detail about alternatives or parameters could be added, but the current length is appropriate.

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 that there are no annotations and no output schema, the description covers the essential context: what the tool does, that it mutates the codebase, and what it returns. It falls slightly short by not mentioning when to choose this tool over siblings or clarifying workingDirectory, but it is largely complete for safe invocation.

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?

The description adds no parameter-level detail beyond the input schema, but the schema already covers 75% of parameters with meaningful descriptions for task, model, and threadId. The workingDirectory parameter lacks a schema description and is not compensated for in the tool description.

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's action: ask Codex to implement a feature, fix a bug, or make code changes. It doesn't explicitly distinguish itself from the sibling review/query/plan tools, but the verb 'implement' and focus on code modification make the purpose clear.

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 the tool should be used when the goal is to modify code, which is helpful context. However, it provides no explicit guidance on when not to use it or how it compares to sibling tools like codex_review_code or codex_query.

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