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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds real behavioral detail beyond that: the lineage is content-addressed, refused hires are included with reasons, and rail calls carry simulated flags — non-obvious traits of the payload that an agent could not get from the annotations.

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?

One front-loaded sentence with no filler; the enumerated return contents are dense but each item conveys distinct information. The long comma list is slightly hard to scan but the leading clause anchors the purpose first.

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?

An output schema exists, so return shape needn't be spelled out, and the annotations cover the safety profile. For a one-parameter read-only tool the description is nearly sufficient; only the job_id-format and job-state edge cases are left unresolved.

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?

The single job_id parameter has 0% schema description coverage, so the description is the only source of meaning. It implies job_id identifies a completed job, but it doesn't state the identifier format, where to obtain it, or what happens if the job is not found or not yet complete.

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 names a specific verb ('Return') and resource ('full content-addressed lineage of a completed job') and enumerates the concrete artifacts returned: plan, hires, contributions, reviews, settlements, rail calls, synthesis. It does not distinguish itself from siblings like job_status or verify_audit, which plausibly overlap, so it stops short of a 5.

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 phrase 'of a completed job' implies a precondition (the job must be finished), which is some guidance, but there is no explicit when-to-use guidance and no mention of when to prefer job_status or verify_audit instead. The agent must infer the routing from sibling names alone.

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