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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe read-only profile is covered. The description adds useful behavioral context about the scope (single US restaurant, three independent price tiers), but much of that overlaps the output schema rather than disclosing new traits like pagination or availability constraints. With annotations doing the safety work, a 3 is appropriate.

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 tightly written sentences with no filler; the resource and its scope are front-loaded and the differentiator sentence follows immediately. Every clause earns its place.

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 a fully described single parameter, an output schema covering return values, and annotations carrying the safety profile, the description supplies everything an agent needs: the exact resource, the store scope, and what the returned menu contains. No material gap remains.

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% and there is only one parameter (store_id), whose origin from /mcdonalds/restaurants is already documented in the schema. The description implies single-store scoping but adds no syntax or format detail beyond what the schema provides, so the baseline 3 holds.

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 (one US McDonald's restaurant's full priced menu) and enumerates what it contains: item name, image, and separate eat-in/pickup/delivery prices. It also explicitly differentiates itself from siblings by claiming to be the only McDonald's endpoint that publishes prices, so an agent can distinguish it from mcdonalds_menu/mcdonalds_item_list without opening the 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?

The line 'The only McDonald's endpoint that publishes prices' gives a clear condition for choosing this tool over the other McDonald's menu endpoints, which is strong routing guidance. However, it never names the alternatives (mcdonalds_menu, mcdonalds_item_list, mcdonalds_item) nor states any when-not conditions, so it stops short of full explicit guidance.

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