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

Annotations already declare readOnly, idempotent, non-destructive behavior, so the bar is lower, and the description adds genuinely new context: an authorization requirement plus the exact overdue computation (invoice date + customer/workspace payment term). It does not describe pagination or ordering, but the safety and permission profile is well covered.

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 sentence with the core scope front-loaded and the permission caveat last. The nested em-dash parenthetical explaining overdue is dense and breaks the reading flow, but every clause carries information.

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 3-parameter read tool with rich annotations and no output schema, the description covers permissions, status semantics, and returned amounts. Ordering and page-size behavior are only in the schema, which is acceptable given the 100% schema coverage.

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 100%, so the baseline is 3, but the description goes further by defining 'overdue' semantically (past due date derived from payment term) and clarifying that customer filtering narrows rather than requires. That adds meaning the enum alone does not convey.

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 concrete resource (invoices) narrowed by status and optionally by customer, and names the returned fields (net and gross amounts). It is specific enough to separate from list_quotations or financial_summary, though it never uses an explicit verb and relies on the title for the 'list' framing.

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?

Includes a hard eligibility constraint ('PMs and admins only') and a default-status implication, which tells the agent when it can call it at all. It never says when to prefer financial_summary, revenue_forecast, or list_quotations over this tool, so the alternatives are left implicit.

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