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

Annotations already declare readOnlyHint=true, so the non-mutating safety profile is structured, not textual. The description adds real domain context — indexes take time and unbuilt maps cause vector search failures — but says nothing about what a status result looks like, error behavior for unknown job_ids, or whether the job record persists after completion.

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?

Three short sentences, front-loaded with the action, then the motivation, then API mapping. The REST endpoint clause is somewhat developer-doc flavored but still compact and non-redundant.

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?

For a single-parameter read tool with no output schema, the description covers what it does, why it matters, and how it maps to the API. The only meaningful gap is that the agent gets no hint about the shape or vocabulary of the returned status.

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% for the single job_id parameter, so the schema already carries parameter documentation. The description only echoes the id inside the REST path and adds no format, source, or acquisition guidance beyond that, making the baseline 3 correct.

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?

States a specific verb and resource: 'Fetch the status of an index-building job.' An agent can distinguish this from siblings like nomic_get_tag_status or nomic_get_dataset because the resource (index job) is explicit. It stops short of naming the sibling it is not, so it lands at 4 rather than 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?

Provides a clear triggering context: use this to determine whether a map/index is ready before a vector search, since 'a vector search against an unbuilt map fails.' This tells the agent when the tool is needed, though it doesn't explicitly point to alternatives for other status-checking needs.

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