List Codex threads

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

Annotations already cover read-only and idempotent safety, so the description adds value by revealing the filtering behavior based on CODEX_ALLOWED_ROOTS and the 'persisted' qualifier. This goes beyond what annotations provide and gives important behavioral context for an agent.

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 two concise sentences. The first sentence states the primary action and scope, and the second clarifies a key behavioral constraint. No unnecessary words or repetition.

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 listing tool with no output schema, the description covers the essential purpose and a key constraint. Combined with the schema and annotations, it provides sufficient context to use the tool, though it could mention pagination or return format explicitly.

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 does not elaborate on any parameters. However, schema descriptions cover 3 of 4 parameters (cwd, cursor, searchTerm), and the remaining limit parameter has min/max constraints. With 75% schema coverage, the description's lack of parameter details is acceptable but not outstanding.

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 uses a specific verb ('List') with a clear resource ('persisted Codex threads') and a scoping constraint (working directories inside CODEX_ALLOWED_ROOTS). This clearly distinguishes it from sibling tools like codex_read_thread (which reads a single thread) and codex_list_approvals.

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 usage by stating the tool lists threads and filters by allowed roots. It gives clear context (listing function) but does not explicitly name alternative tools or exclusions. The mention that results outside allowed roots are filtered provides actionable guidance about when this tool is appropriate.

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