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

With no annotations, the description carries the full burden; it does disclose that output shape changes with the input (filtered day results include times, unfiltered returns everything). It does not state that this is a read-only public lookup, how invalid day values behave, or whether pricing/discount details are included.

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, front-loaded with what the tool returns and followed by the conditional behavior of the day argument. The parenthetical offer list is long but functions as concrete scoping evidence rather than padding.

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?

For a single optional parameter, no output schema, and no annotations, the description covers what is returned, how the parameter modifies the result, and what the default is. Nothing an agent needs in order to call this correctly appears to be 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% and the schema already documents accepted day formats and the omit-for-full-list default. The description adds only that day-filtered results come with times, a marginal increment over the schema rather than new syntax or constraints.

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 the resource precisely as promotions and recurring offers, and illustrates with concrete named offers (happy hour, Wine Wednesday, Supper Club), so an agent knows exactly what content this returns. It does not, however, distinguish itself from the sibling get_early_bird even though it lists Early Bird as one of its own categories, leaving a potential overlap unresolved.

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?

Gives a clear conditional usage rule: passing a day narrows results to that day with times, and the full list is the default. It stops short of saying when to prefer get_early_bird over this tool for Early Bird offers, so tool selection against that sibling still requires inference.

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