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

With readOnlyHint already covering safety, the description adds valuable behavioral detail: date defaults to today in the business timezone, started slots are excluded, closed days return none with a reason, no-reservation businesses return a reason plus opening hours, and unresolvable names are refused rather than silently mapped to another business. This goes well beyond the annotation baseline.

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?

Although the description is long, every sentence contributes essential invocation or edge-case information. It front-loads the core purpose, then covers defaults, return behavior, and name resolution without fluff or repetition of annotation data.

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?

Given no output schema, the description explains what is returned: open slots with stable slotIds, no-slot and closed-day responses, and opening hours for no-reservation businesses. Combined with the rich input schema, an agent has everything needed to call this tool correctly.

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 description adds meaning on top: it explains the business parameter accepts a name or id, gives concrete examples, describes the refusal behavior, and clarifies businessId as an alias ignored when business is provided. This is exemplary parameter-level guidance.

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?

The description states a specific action and resource: 'Open appointment slots at a business served through this connector, for one date.' It clearly distinguishes itself from sibling tools like biz_info and biz_menu because it is about open reservation slots, not business info or menus.

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 description gives strong context: one date, optional business parameter, and default business behavior. It does not explicitly name alternative tools or say when not to use this one, but the clear focus on appointment slots makes the intended use apparent.

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