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

Annotations already establish the tool is read-only, idempotent, and non-destructive. The description adds useful behavioral context by describing the date-bound aggregate output and signaling a Pro requirement. It does not detail response structure or error behavior, but the annotation coverage lowers the burden for this read-only report.

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 tight sentences with no filler. The core behavior and output highlights are front-loaded, and the Pro/alternative note is packed into a short second sentence.

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 tool with two optional, fully described parameters and no output schema, the description enumerates the key returned information: totals, aging per currency, overdue ranking, and oldest overdue invoice. The sibling pointer and annotations complete the picture, and openWorldHint=false supports treating the description as sufficient.

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%, and both parameters already carry clear meaning in the input schema: as_of is the aging date, and limit controls how many clients to list worst-first. The description echoes this and adds no materially new parameter-level semantics, so the baseline of 3 applies.

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 clearly states the tool reports receivables across every client at a date, including totals, aging per currency, overdue ranking, and the oldest overdue invoice. It also distinguishes itself from the per-client sibling, statement_aging, so an agent can identify the right scope without opening schemas.

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?

It explicitly names the alternative: 'statement_aging is the free per-client view.' The 'Pro' flag and the contrast between 'every client' and 'per-client' give an agent clear conditions for choosing this tool over its sibling.

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