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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds meaningful context beyond that: the report is built only from documents still unpaid at dateTo, and it returns only the report (no exchange rates). It stops short of describing pagination or bucket definitions, but this is solid supplemental disclosure.

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 sentences with zero padding; the primary purpose is front-loaded and the sibling routing follows. Every clause carries information, including the useful 'returns only report' distinction.

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 takes on the job of describing the return shape, and it does so ('grouped by contact into aging buckets', 'returns only report'). Combined with full schema coverage and supporting annotations, an agent has enough to call it correctly; only finer details of bucket composition are left implicit.

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 all three parameters are already documented in the schema, including the note that dateFrom is unused. The description reinforces the dateTo as-of semantics but adds no format or syntax detail beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (Get) and resource (aged receivables report), and immediately defines the semantics: outstanding amounts owed as of dateTo, grouped by contact into aging buckets. It explicitly distinguishes itself from get-aged-receivables-v2 and get-overdue-invoices, so an agent can tell them apart without opening any schema.

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?

Provides explicit routing rules: use get-aged-receivables-v2 for the ledger-based report that also returns exchange rates, or get-overdue-invoices for past-due buckets only. This names both alternatives and the conditions that select each, 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.