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

No annotations present, so description carries full burden. It mentions 'preserves context' but does not disclose side effects (e.g., sandbox permissions, file writes, terminal output). The schema covers some details, but the description itself lacks deeper behavioral traits like auth needs or rate limits.

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?

Extremely concise at two sentences. The first sentence clearly states the action and method; the second adds the key benefit of context preservation. No fluff, front-loaded.

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?

Despite having 9 parameters and an output schema, the description omits important context like the dependency on codex_execute to obtain sessionId, or the streaming behavior indicated by the terminal parameter. It is adequate but leaves gaps for a complex 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 coverage is 100% with detailed parameter descriptions. The tool description adds no extra meaning beyond 'sessionId' and 'prompt'. Baseline 3 is appropriate since schema does the heavy lifting, but the description could briefly highlight key optional params.

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?

Clearly states the verb 'Resume' and the resource 'Codex session' with the method 'by sessionId with a follow-up prompt'. It distinguishes from siblings like codex_execute (which starts new sessions) and codex_sessions (which lists them) by emphasizing resuming an existing session and preserving context.

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?

Explicitly says 'Resume an existing session' and gives a typical use case 'review feedback'. This implies when to use (when you have a sessionId) and implicitly when not (for new sessions, use codex_execute). No explicit alternatives or exclusions, but context is clear.

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