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

Annotations already declare readOnlyHint and openWorldHint, and the description adds real value on top: item ids are market-specific, and the result contains no prices. The market-specific id warning is a genuinely useful behavioral caveat that prevents cross-market id misuse, though return format/pagination is not covered.

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 compact sentences, front-loaded with what the tool returns, then the key caveats. Every clause earns its place with no filler.

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?

An output schema exists so return values need not be detailed, annotations cover the safety profile, and the schema documents both params. The description supplies the essential scope caveats (one market, market-specific ids, no prices), leaving only sibling routing unaddressed.

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 both parameters (category, country) are already documented with the market list and the source of the category slug. The description reinforces the single-market constraint and the market-specific id behavior but adds no new syntax or format detail. Baseline 3 applies.

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: a McDonald's menu category listing for one market, and enumerates the returned fields (item ids, names, product URLs, images). This distinguishes it from siblings like mcdonalds_categories and mcdonalds_item without naming them explicitly, so it is clear but not fully sibling-differentiated.

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?

Implies the preconditions (one market, a category slug) and adds a scope note (no prices), but never states when to use this versus mcdonalds_item, mcdonalds_item_list, or mcdonalds_restaurant_menu. Usage is inferable rather than spelled out.

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