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

Annotations already declare the safe read-only profile, but the description goes further by disclosing the return shape: grouping by supplier, one line per document, the exact aging buckets (Current, < 1 Month, 1/2/3 Months, Older at 30-day steps), and that totals are in the company's base currency. The one remaining gap is pagination/size behavior, which is unaddressed.

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?

Purpose and scope are front-loaded in the first clause, and the routing sentence comes last where it is most useful. It is dense and long, but nearly every clause carries information an agent needs; minor trimming would still be possible.

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 carries the burden of describing the return value, and it does so thoroughly: grouping, line contents, aging buckets, and currency of totals. Combined with 100% parameter coverage, nothing material is missing for correct invocation.

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 baseline is 3. The description reinforces the as-of semantics of dateTo ('as of dateTo') but adds no syntax or format details beyond what the schema already documents for id, dateTo, and the unused dateFrom.

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 and resource ('Get the aged payables report for a company') and immediately defines the scope: supplier obligations from approved, still-unpaid purchase documents as of dateTo. It is unmistakably distinct from get-aged-receivables, which it names directly.

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?

Explicitly routes the agent: 'Use get-aged-receivables for what customers owe, or get-invoice-pending-summary with movement out for payables totals only.' Both the alternative tool and the condition selecting it are given, leaving nothing to inference.

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