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

Annotations cover the safety profile (readOnlyHint=true, openWorldHint=true), so the description carries a lighter burden. It adds that the response is per-component and richer than a single-item lookup, which is useful behavioral context, but doesn't note pagination, item-limit consequences, or return shape (though an output schema exists).

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?

Single sentence, front-loaded with the resource, and the scope details come in the same breath. No filler, though it's brief enough that some guidance is arguably missing rather than trimmed.

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?

Two-param read-only tool with a 100%-documented schema and an output schema, so return values need no explanation. The description is complete enough for an agent to call it correctly; the only gap is explicit routing to sibling lookup tools.

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 parameters (country, item_ids) are documented in the schema, including the enum set of markets and the 20-item limit. The description repeats the item-limit but adds nothing beyond the schema for country syntax or id format. Baseline 3.

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 (detail retrieval) and resource (McDonald's nutrition/allergen data) and adds scope (up to 20 items, per-component breakdown). It doesn't explicitly name which sibling it differs from, but it does say 'a single-item lookup does not expose', implicitly distinguishing from mcdonalds_item.

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 is implied by the mention that per-component breakdown is only available in batch, but there is no explicit when-to-use guidance nor a named alternative (e.g., use mcdonalds_item for a single product).

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