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

Annotations declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, and the description explains exactly why: the click is counted for the business, and booking/payment are handed off to an external page. That is real added context beyond the structured flags.

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 short sentences with the eligibility condition front-loaded and zero filler; each clause carries distinct information (precondition, action, side effect, where the transaction completes).

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-style tool with no output schema, the description covers what is returned (a link) and the external handoff. It doesn't say what happens if the business is not in external_link mode, or whether links expire, which would round it out.

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 each field already says where the ID comes from (get_business, search_businesses). The description contributes no further parameter meaning, so the baseline 3 applies.

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 (get a link to the business's own booking page for one service) and names the precondition (booking_mode is external_link). It also draws the boundary that booking and payment do not happen here, which separates it from request_booking/complete_booking.

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 precondition "For businesses whose booking_mode is external_link" gives a clear condition for selecting this tool and implicitly excludes the in-platform booking siblings. It stops short of naming an explicit alternative for the non-external_link case.

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