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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered elsewhere. The description adds that the result is a *signed* chain for a single job, which is useful behavioral substance, but says nothing about auth needs (the apiKey path), freshness, or completeness of the chain.

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?

Two terse sentences, resource first, constraint second – nothing wasted and it is front-loaded. It reads more as under-specification than as tightness, but structurally it is clean.

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 tool is simple (two params, one required) which lowers the bar, but with no output schema the description should say what a receipt chain contains or what an agent can do with it. The apiKey credential path is left entirely to the schema.

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 50%: apiKey is documented in the schema, while jobId has no description there. 'Needs jobId' only restates what the required array already enforces and adds no meaning about identifier source or format, so the partial coverage gap is not compensated.

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?

Names a specific resource ('signed receipt chain') scoped to one job, which is distinguishable from siblings like get_job or get_check. It omits an explicit verb (get/return), leaving the agent to infer retrieval, but the resource specificity carries it.

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?

'Needs jobId' is a parameter note, not usage guidance. There is no indication of when to call this instead of get_job, get_check, or deliver, and no prerequisites or exclusions are stated.

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