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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description earns credit beyond that by disclosing the output shape (buckets plus underlying invoice detail) and the exact bucket boundaries (current / 1-30 / 31-60 / 61-90 / 90+) and the aging basis (invoice due date) — behaviour an agent cannot get from the annotations.

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?

Three short sentences, front-loaded with what the report contains, then the routing intent, then the bucket definitions. No filler and nothing repeated from the schema or annotations.

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 must carry return-value information and it does: buckets plus invoice-level detail, with bucket edges spelled out. The one meaningful gap is whether the report is broken down per customer or is a single company-wide aggregate — relevant given the adjacent o2c_customer_statement and solo_outstanding tools.

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% for the single `as_of` parameter, including its default of today and ISO YYYY-MM-DD format, so the schema does the heavy lifting. The description only indirectly implies the aging basis ('against the invoice due date') without ever mentioning the as-of date parameter, so it adds no parameter meaning beyond the schema. Baseline 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 names a specific artifact (open receivables bucketed by days past due) and its internal structure (invoice-level detail behind each bucket), which is far more than a restatement of the title. It does not explicitly differentiate itself from near-neighbours like o2c_customer_statement, solo_outstanding, or o2c_unapplied_cash, so an agent must infer the boundary from the bucket definition 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 report to open when asked how the business is doing on cash' gives a concrete triggering intent, which is exactly the routing signal an agent needs. It stops short of naming an alternative or an exclusion (e.g. per-customer statements), so it is clear context without full when-not guidance.

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