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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuine behavioral value by describing the kind of payload returned (choice steps, surcharges, ingredient rules), though it says nothing about pagination, rate limits, or market availability quirks.

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?

Three sentences, zero filler, front-loaded with the payload description before prerequisites and the sibling pointer. Each sentence 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?

Output schema exists so return values need not be explained, both parameters are documented in schema and description, and the sourcing prerequisite for offer_id is covered. Nothing needed to invoke the tool 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 coverage is 100%, so the baseline would be 3, but the description adds provenance for offer_id (it must come from papajohns_intl_deals) and reiterates the market constraint, which helps an agent obtain a valid value rather than just documenting the field type.

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?

Specific verb ('Fetch') plus resource ('one Papa John's international promotion's offer details') and an enumeration of what that detail includes (choice steps, eligible products, surcharges, ingredient rules). It names the sibling it is not (papajohns_intl_product), so an agent can distinguish it from adjacent tools.

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?

Explicitly states the prerequisite for the id ('Get offer_id from papajohns_intl_deals'), enumerates the valid market values, and routes the agent to papajohns_intl_product when a single product's details are wanted. Both the when and the alternative are stated.

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