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

Annotations already cover the read-only and open-world profile, and the description adds the non-obvious auth requirement (Admin role) plus the aging/outstanding-balance framing that annotations cannot convey. It stops short of disclosing result shape, pagination, or what happens with an unbounded period.

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 permission gate and the report's content both front-loaded; nothing is redundant or padded.

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 read-only report with fully documented parameters and no output schema, the definition covers purpose, audience, and access control adequately. It could say more about default period behavior or grouping defaults, but nothing essential to invocation is missing.

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 seven optional parameters (start/end, group_by, client/matter/user/practice ids) are already documented at the field level. The description adds no filtering or grouping guidance beyond that, making the baseline 3 the correct call.

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?

States a specific verb+resource: an accounts-receivable report of unpaid invoices aged by bucket, with the clarifying gloss 'who owes the firm what'. It is meaningfully distinct from list_billing_items or report_payments_collected, though it never names those siblings to sharpen the contrast.

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 Admin-role prerequisite is stated, which is real routing information, but nothing tells the agent when to pick this over the nearby lawcus_report_invoice_history or lawcus_report_matter_balance siblings, nor whether the period parameters are required in practice.

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