List Codex threads

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

Annotations already provide readOnlyHint=true and openWorldHint=true, so this is clearly a non-destructive operation. The description adds value by specifying the exact output fields and its purpose, which is especially useful since no output schema is present. It does not describe sorting or the exact source scope, but the annotations lower the bar for side-effect disclosure.

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 a single sentence that front-loads the verb, resource, and output fields, then states the practical purpose. There is no redundant filler or repetition of schema content.

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 read-only list tool with a fully described schema and no required parameters, the description is nearly complete: it names the output fields and the intended follow-up action. It could be slightly more explicit about whether it lists only app-server-loaded threads or all persistent threads, but the loadedOnly parameter and sibling context make this a minor 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 description coverage is 100% and every parameter (cwd, limit, loadedOnly, searchTerm) already has a meaningful description, including the default limit of 15. The description adds no additional parameter-level meaning, so the baseline of 3 is appropriate.

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-resource pair ('List recent Codex threads') and enumerates the returned fields (id, title, cwd, last update, status). It also gives a clear goal — picking the exact threadId to talk to — which distinguishes this read-only listing tool from sibling action tools.

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 when to use the tool: before interacting with a thread, when the agent needs to resolve a threadId. It does not explicitly name sibling alternatives or state when not to use it, so it stops short of a 5.

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