nexus_job_cost

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds a small constraint that the job must already exist ('existing job'), but does not describe error handling or other behaviors. It does not contradict the annotations, but also offers minimal extra behavioral 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?

A single, concise sentence delivers all necessary information: the action, resource, and required input. There is no redundancy or filler, making it optimally concise and well-structured.

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 simplicity, the existence of an output schema (which documents return values), and rich annotations, the description is sufficiently complete. It clearly states the input requirement and purpose. The only minor gap is the lack of error behavior or cost format, but these are not essential for a simple read-by-id operation.

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 0%, and the description only says 'by id', which does little beyond the parameter name job_id. However, the parameter is simple and self-explanatory, and the phrase 'existing job' implies the ID must refer to a valid job, adding slight semantic value. It does not fully compensate for the lack of schema documentation, but the parameter is straightforward.

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 clearly states the action ('Return') and the resource ('HQC cost of an existing job'), with a precise scope ('by id'). It is distinct from sibling tools like nexus_job_status and nexus_get_results, which focus on status or results respectively, making the purpose unambiguous.

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 gives a clear context: use this when you need the HQC cost for a specific job ID. It does not explicitly mention when not to use it or alternatives, but the context is so specific that usage is evident. The lack of exclusions is acceptable given the tool's narrow scope.

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