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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds that it returns IDs and values and that it precedes a line edit, but gives no return format, ordering, or error behavior, leaving some behavioral gaps.

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 front-loaded sentence with no waste; both the purpose and the precondition are stated efficiently.

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 one-param read tool with annotations covering the safety profile, the description is largely adequate, but with no output schema it could better describe the returned shape (e.g., IDs and values, ordering) to be fully complete.

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 0% and the single required parameter is a UUID invoice_id with no description. The description implies the input is 'an invoice' but adds no format, validation, or meaning beyond what the schema title implies, so it does not compensate for the coverage gap.

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 (Read) and resource (saved line-item IDs and values for an invoice). It is clearly distinguishable from edit_invoice_line_item, add_invoice_line_item, and remove_invoice_line_item by the 'read' framing, though it does not explicitly reference those siblings.

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 'before making a precise line edit' gives a concrete usage condition, telling the agent to call this prior to editing. However, it does not name explicit alternatives or state when not to use it.

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