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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower. The description adds real behavioral context: the price is store-specific, and the selection returned spans size, crust, and preparation choices, which tells the agent what a single call yields. It does not mention error behavior for invalid SKUs, but this is a solid additive disclosure.

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 sentences, zero waste. The capability and return shape come first and the sibling routing follows, which is the correct front-loading order.

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-value detail need not be restated, and the description instead supplies the two things the structured fields don't: geographic scope and the store-vs-national pricing consequence. Nothing needed to call it correctly is missing.

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 are already documented in the schema, including that store_id controls which restaurant's price applies and that omission yields the national default. The description's "with its store price" echoes this without adding format, valid-value, or sourcing detail, so it sits at the 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 (Fetch), a precise resource (one Papa John's US or Canada menu SKU), and the scope of what is returned (store price plus available size, crust, and preparation choices). The US/Canada qualifier separates it from the intl and country-specific siblings (papajohns_india_menu_item, papajohns_intl_product), so the agent can identify it without opening schemas.

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?

"Use papajohns_menu to browse a store's menu" names the sibling and the condition that selects it, which is clear routing. It does not explicitly state the inverse (use this tool when you already have a SKU from the menu listing), but that condition is strongly implied by the required sku param and the sibling pointer.

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