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

Annotations only cover readOnlyHint and openWorldHint, and the description usefully adds the return shape (date, reason, risks, measures, lots), the meaning of all_lots=false, and the crucial caveat that a source with backfilled=false may be missing older recalls. What it does not cover is whether the check is rate-limited or how far back each source reaches.

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?

The purpose is front-loaded in the first clause and every subsequent sentence carries a real detail about output interpretation or freshness. It is somewhat run-on and parenthesis-heavy, but no sentence is wasted.

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?

There is no output schema, so the description must carry the return semantics, which it does: it explains what recalled true returns, what recalled false includes (checked_at, per-source freshness), and the backfill caveat. Only source coverage depth and error behavior are left unstated.

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 single gtin parameter is already documented as 8-14 digits with spaces allowed. The description restates accepted barcode families (GTIN/EAN-13, UPC-A, EAN-8) but adds nothing about normalization or digit-count edge cases, so the schema still 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?

The description names a specific verb (checks), resource (product recall), the two data sources (RappelConso for France, Safety Gate for the EU), and the accepted identifier formats. It is clearly distinguishable from siblings like list_recent_recalls, though it never names that sibling 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?

Usage context is implied rather than stated: the caller is told to "compare the lots with the product at hand" and how to read recalled true/false. There is no explicit when-to-use-this-vs-alternatives guidance, so an agent must infer that a single-barcode lookup is different from a recent-recalls listing.

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