List Codex models

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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context by saying it reads live from the Codex model catalogue and is never hardcoded, but it does not mention the 60-second cache behavior, and 'read live' slightly overstates freshness for a tool whose refresh parameter implies cached results by default.

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 short sentences, each earning its place: the main action, the data-source caveat, and the usage routing. It is front-loaded with the core purpose and contains no fluff.

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 read-only list utility with one optional parameter already fully documented in the schema, the description covers purpose, account scope, output content (models plus reasoning-effort levels), and when to use it. The output expectation is clear even without an output schema.

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%; the refresh parameter is already documented as bypassing the 60s catalogue cache and re-reading from Codex. The description adds no parameter-level meaning, so the baseline 3 applies.

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 ('List'), a clear resource ('Codex models available to this account'), and a key included detail ('reasoning-effort levels each one supports'). This clearly distinguishes it from sibling tools like codex_get_limits or codex_delegate without needing to inspect their schemas.

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 explicitly tells the agent when to call it: before codex_delegate, when matching model strength to task difficulty. This gives concrete, decision-relevant routing to a sibling tool.

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