Fetch job result (free)

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

The description discloses error envelopes for running/cancelled/timed-out/failed jobs, notes the job_result_incompatible case, and clarifies it makes no model call ('Free'). It also explains the default detail behavior and workspace_root fallback warning. These go well beyond the annotation's readOnlyHint=true, adding valuable edge-case context.

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?

Though the description is longer than one sentence, every clause carries purpose: purpose, scope, when-to-use, error behavior, alternative tool, and parameter hint. It is front-loaded with the core action and then logically branches into details. No fluff or redundancy.

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?

The description is complete for the tool's complexity: it addresses the full lifecycle (fetch vs consume), the relationship to job_status, error conditions, the return envelope 'branch on tool', and the parameter behavior. The presence of an output schema means return value details don't need to be reiterated, and the description covers everything else an agent needs to select and invoke correctly.

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%, so the description doesn't need to explain parameters from scratch. It does add usage context for job_id (sources from async calls or meta.job_id) and explains the detail parameter's effect, but these largely mirror the schema. The workspace_root parameter is only described in the schema. Given the schema already carries the meanings, a baseline 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 immediately states the tool's exact action: 'Fetch a finished background Kimi job's result WITHOUT deleting the record.' It also differentiates from the sibling kimi_job_consume_result (which fetches and deletes) and lists the specific job types covered. The verb 'fetch' plus resource 'job result' plus the non-destructive qualifier makes the purpose unmistakable.

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 states when to use: 'Use when kimi_job_status reports result_available=true.' It also mentions the alternative for fetch-and-delete ('use kimi_job_consume_result') and lists compatible source tools (delegate_async, consult_async, review_changes_async). This provides clear when/when-not guidance relative to siblings.

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