Continue Codex session

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

The description adds valuable behavioral context beyond annotations: it explains session resumption logic, fallback behavior, and that the session keeps its original sandbox and model. No contradictions with annotations (readOnlyHint=false, idempotentHint=false, openWorldHint=true) are present.

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 concise, with two short paragraphs. The first sentence front-loads the primary purpose. Every sentence adds value, with no redundant or irrelevant information.

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?

Given the tool's complexity (4 parameters, 1 required), schema coverage (100%), and the presence of an output schema, the description covers all key aspects: session identification, fallback, behavior after restart, and preservation of original settings. It is complete for an agent to correctly invoke the tool.

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%, so the baseline is 3. The description does not add significant extra meaning for parameters beyond what is already in the input schema schema. It provides context around workspace defaults and timeout, but these are already described in the schema.

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 that the tool continues an existing Codex session, using a specific command (`codex exec resume`). It distinguishes from sibling tools like codex_ask (which starts a session) and codex_status (status check), and explains the fallback behavior for session identification.

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 explains when to use this tool (after codex_ask, to continue a session) and includes practical details like fallback after server restart. It does not explicitly state when not to use it or mention alternatives, but the context is clear enough for an agent to infer appropriate usage.

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