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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false) by disclosing side effects: the contact becomes a customer once the appointment is on the calendar, recurring frequency creates a recurring service, and per-call confirmation is on by default. It also flags the Cotlet API key requirement. It doesn't cover failure modes or scheduling conflicts, so not a full 5.

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?

The purpose is front-loaded correctly, but the description runs about eight sentences with redundancy ('Schedule'/'Books an appointment... with a start and end time') and platform boilerplate about the API key and confirmation toggle. Several sentences could be trimmed without losing information.

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 9-parameter create tool with no output schema, the description covers the required inputs, the two tricky optional fields, and the side-effect/confirmation behavior. Minor omissions (service_type, notes semantics) are self-explanatory from the schema and don't block correct invocation.

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%, so the schema already documents all nine parameters, including the empty-value behaviors for cleaner_ids and price. The description's parameter notes (unassigned cleaners, calculated price, frequency) largely restate the schema, so the 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 ('Schedule a one-time or recurring appointment for a contact') and clarifies it books for an existing contact. An agent can distinguish this from zenmaid_reschedule_appointment, zenmaid_cancel_appointment, and zenmaid_list_appointments without opening any schema.

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 concrete usage conditions: leave cleaner_ids empty to keep it unassigned, leave price empty to let ZenMaid calculate, and use a recurring frequency to create a recurring service. It never names a when-not-to-use case or points to a sibling tool, so it stops short of full routing guidance.

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