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

With no annotations, the description carries the full burden; it usefully discloses the return fields, descending sort, and that totals are kept per currency rather than converted into one figure. It does not mention read-only safety, default filtering of draft/cancelled documents, or behavior when currency is omitted.

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 waste; the ranking purpose and the date-range scoping come first, followed by the returned fields. Nothing is repeated from the schema.

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 analytics tool with no output schema, the description adequately explains what comes back and in what order. It could still note the default top-10 limit and the default "issued" state filter, but the schema covers both.

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% and the parameters are well documented there, including the "issued" state alias and inclusive date bounds, so the baseline applies. The description only gestures at "date range" and "per currency" and adds no syntax or default information beyond the schema.

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 ("Rank clients by total invoiced amount") plus the aggregation scope (date range) and output shape (name, total, invoice count, sorted descending). That is enough to separate it from report_invoiced_by_period or invoices_summary, though it never names those siblings explicitly.

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?

No when-to-use or when-not-to-use guidance and no mention of alternatives among the many report_* and search_* siblings. The only contextual cue is the implicit date-range filter, so an agent must infer selection from the name alone.

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