Validate Invoice Data

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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds the substantive detail that this is a pre-booking guardrail check on EUR rates, but it does not disclose what a failed validation produces (errors vs. warnings) or whether it blocks booking.

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?

A single, information-dense sentence with the scope of validation front-loaded and the timing constraint ('before booking') at the end. No filler or redundancy.

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?

All parameters are documented and annotations carry the safety profile, but with no output schema the description leaves the return/failure behavior unexplained – an agent cannot tell whether a bad input yields an error, a warning list, or a boolean. Minor gap for a read-only tool but a real one.

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 all 11 parameters are already documented in the schema. The description's mention of totals, item totals, dates, and rate guardrails maps to the params but adds no format, default, or boundary detail beyond what the schema provides – the baseline for full coverage.

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 (validate) and resource (extracted invoice data) with concrete scope: totals, item totals, dates, and foreign-currency EUR-rate guardrails. This distinguishes it from mutation siblings like confirm_purchase_invoice, though it does not explicitly name a sibling it contrasts with.

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 phrase 'before booking' implies the correct usage window (a pre-booking check), which is useful context. However, it names no alternatives and gives no when-not guidance, even though sibling preview_purchase_invoice_totals_correction plausibly overlaps.

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