Fetch job result (free)

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

Annotations already mark the tool readOnlyHint=true and openWorldHint=false, and the description reinforces this with 'WITHOUT deleting the record.' It adds substantial behavioral context beyond annotations: error envelopes for various job states, the job_result_incompatible limitation, the envelope shape matching the job kind, and the 'free' nature with no model call. No contradiction 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 front-loaded with the core purpose and then organized into applicability, usage, error behavior, alternatives, cost, and parameter notes. While longer than a trivial tool's description, every sentence carries operational value; a small amount of repetition (e.g., meta.job_id mentioned twice) keeps it from a perfect score.

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 moderate complexity and the presence of an output schema, the description is fully complete. It covers prerequisites, error scenarios, the relationship to sibling tools, the optional detail parameter, and cost implications, giving an agent everything needed to invoke the tool correctly without needing to infer behavior.

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 baseline is 3. The description mostly restates schema-provided parameter details (e.g., detail='summary' vs 'full') and adds no genuinely new parameter semantics. It mentions meta.job_id is set, which relates to input provenance but not a distinct parameter detail, so it does not raise the score above baseline.

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 opens with 'Fetch a finished background Codex job's result WITHOUT deleting the record,' which states a specific verb, resource, and key qualifier (non-destructive). This clearly distinguishes it from codex_job_consume_result, and the subsequent enumeration of supported job types removes ambiguity about scope.

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 explicitly says 'Use when codex_job_status reports result_available=true' and identifies codex_job_consume_result as the alternative when deletion is desired. It also names sibling tools and clarifies when this tool should not be used (e.g., errors for still-running/cancelled/timed-out/failed jobs), providing strong decision guidance.

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