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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lowered. The description usefully adds that results are restricted to restaurants where the dining credit works, but says nothing about result count, ordering, or the meaning of the limit cap in practice.

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?

One sentence, no filler, with the resource definition front-loaded and the two lookup modes trailing. The parenthetical explaining the dining credit is the only aside and it earns its place by clarifying the filter's meaning.

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 no output schema and four undocumented parameters, the description should say more about what is returned and what happens when the tool is called with no arguments. It covers the core intent but leaves the agent guessing about result shape and default behavior.

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 0%, so the description must compensate. It implicitly maps lat/lng to the 'nearest to a point' mode and city to the 'by city' mode, covering three of four parameters, but never mentions limit (max 20) or gives any format/coordinate-system detail.

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 (find) and a precisely scoped resource: Sapphire Reserve Exclusive Tables restaurants where the $300/yr dining credit applies. This is distinguishable from siblings like sapphire_reserve_credits (credit info) and search_edit_hotels (hotels) without opening any 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 phrase 'by city, or nearest to a point' implies the two supported lookup modes but never states when to pick one over the other, nor what happens if no parameters are supplied (required parameters: 0). Usage is inferable but not explicit, and no alternatives are named.

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