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

The annotation readOnlyHint=true already declares this as a safe read operation, so the description need not repeat that. The description adds useful field-level detail about what is returned and the underlying endpoint, but it does not disclose auth requirements, pagination behavior, rate limits, or output ordering.

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 compact sentences with no wasted words. The scope and return fields are front-loaded, and the API endpoint is placed at the end as supplementary context.

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?

With no output schema, the description does a good job of listing the fields returned by the tool, which is the main thing an agent needs. Minor omissions such as pagination behavior or result limits prevent a perfect score for a list 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 100%, so the single required parameter is already documented by the schema. The description implies that job_id scopes the result to one job, but adds no format, validation, or example beyond what the schema provides, making the baseline 3 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 states a specific verb (List), resource (invoices), and scope (for one job), making it clearly distinct from the company-wide list_invoices sibling. It also previews the returned invoice fields, which confirms the tool's purpose beyond the name alone.

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 'for one job' gives clear context for when to use this tool rather than a global invoice listing, and the endpoint path reinforces the job-scoped intent. However, it does not explicitly name alternatives such as housecall_list_invoices or state when this tool should be avoided.

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