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

Annotations cover the read-only/open-world safety profile, but the description adds critical behavior the annotations cannot convey: opening hours are only available for paid Bezal plan providers, and other listings return open as "unknown". It also discloses the bookings blind spot, which materially affects how an agent should interpret and act on the result.

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, each earning its place: purpose first, then the data-availability constraint, then the practical limitation. No repetition or padding, and the most important caveat is front-loaded after the purpose.

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 two-parameter read tool with no output schema, the description covers purpose, data availability semantics, the meaning of an "unknown" result, and the confirm-with-business caveat. An agent has everything it needs to call and interpret this 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 description coverage is 100%, with both business_id and date fully documented (UUID and ISO YYYY-MM-DD). The description adds no parameter-level detail, so the schema is doing all the work here; baseline 3 is appropriate.

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 and resource: checking whether a business is open on a given date based on posted opening hours. This is clearly distinct from siblings like get_business or search_businesses, which retrieve entity data rather than availability.

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 clear when-to-use context and a strong when-not-to-rely caveat: it doesn't know about bookings, so a time should be confirmed with the business. It also states the paid-plan restriction. It does not explicitly name alternative sibling tools, but the usage boundaries are otherwise clear.

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