Peek at Codex

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

With no annotations, the description carries the full burden. It usefully discloses that the call is non-blocking and returns current activity plus pending requests, which is real behavioral context. But it says nothing about whether it mutates state, whether calling it has side effects, or any auth/permission requirements.

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?

One compact sentence front-loads the key trait ('Non-blocking snapshot') and then enumerates the payload. No filler or redundant restatement of the tool name.

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 simple, zero-required-parameter read tool with full schema coverage and no output schema, the description covers what the agent needs: it is non-blocking and what information it surfaces. Sibling differentiation is implicit rather than explicit, which is the main gap.

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% and the single optional parameter is fully documented in the schema ('Defaults to every thread used in this session'). The description adds no parameter-level detail beyond that, 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?

States a specific verb+resource: a non-blocking snapshot of Codex threads, returning status, activity, and pending requests. The scope ('in this session') and the read-only framing distinguish it from siblings like codex_run, codex_wait, and codex_interrupt.

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 'non-blocking' framing implies this is the polling/inspection tool to use instead of blocking calls like codex_wait, and 'peek' signals an observation-only call. However, it never explicitly says when to use this versus codex_wait, codex_threads, or codex_status alternatives, so routing is left to inference.

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