codex

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

Discloses blocking behavior, git worktree creation for full-access, and return values (final result, session_id, git diff stats). No annotations are present, but description handles behavioral disclosure well without contradictions.

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 concise sentences with no redundancy. The primary purpose is front-loaded, and each sentence adds necessary information without superfluous 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?

Provides adequate overview of behavior and return values. However, several parameters (cwd, topic, prompt) are not fully explained, and the output schema is not detailed. Given the tool's complexity, slightly more detail would improve 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 description coverage is low (20%). The description adds value for 'sandbox' (already described in schema) and 'session_id' (resume context). However, 'prompt', 'cwd', and 'topic' lack explanation, requiring some inference from parameter names.

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 'Execute a Codex task and block until completion,' specifying the verb and resource. It distinguishes from siblings like codex_cancel and codex_dispatch by highlighting synchronous behavior.

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 on when to use read-only vs full-access sandbox modes ('Use read-only sandbox for reviews/analysis, full-access for code modifications'). Lacks comparison with sibling tools but adequately covers the key parameter choice.

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