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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true; the description adds the important auth constraint (owners only, sign-in required) and the availability validation rule. It does not disclose side effects such as customer notifications, whether the call fails when the slot is taken, or whether missing phone/email changes downstream behavior beyond 'is fine'.

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?

It is short and front-loads the permission gate ahead of purpose, which is good ordering. The phrasing is telegraphic and uneven ('selections are from catalog', 'Any time works with any_time'), making a few sentences harder to parse than necessary without adding precision.

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 high-stakes creation tool with 11 parameters, a nested selections array, and no output schema, the description covers the permission requirement and the key scheduling constraint but omits most field meanings and the expected response. The gaps are moderate rather than fatal, since the core call shape can be inferred from required fields.

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% across 11 parameters, so the description must carry the semantics and it does not. It explains only three loosely: selections come from the catalog, any_time overrides the open-slot requirement, and phone/email are optional; 'start', 'who', 'address', 'zip', 'note', 'lead_id', 'customer_name', and the entire nested selection shape (item_id, quantity, options, fields) are never addressed.

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 uses a specific verb and resource ('Add a booking') and enumerates intake channels ('from a call, a walk-in or anywhere else'), which clearly separates it from siblings like cancel_booking or move_booking. It also ties the booking contents to the catalog, but stops short of naming any sibling explicitly.

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?

It gives real preconditions ('Owners only (needs sign-in)') and a scheduling rule ('Any time works with any_time; otherwise it must be open'), which is useful when-to-use context. However, it never says when to prefer this over request_booking, book, or add_receptionist_source, so the choice among creation paths is left to inference.

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