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

Beyond the annotations (readOnly=false, destructive=false, openWorld=true) it discloses concrete side effects and constraints: the customer receives Momence's booking notice, the call reaches other people and needs user confirmation, the tool needs a Cotlet API key with app access, and the default confirmation can be disabled. This is meaningful behavioral context an agent cannot get from the structured fields.

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 core purpose is front-loaded and the sentences are individually clear, but sentence two largely repeats sentence one ('Adds a customer to a class, or to its waitlist when waitlist is true'), and the confirmation/auth notes add some length. Mostly efficient with minor redundancy.

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 mutation tool with no output schema it covers return values (booking_id or waitlist position), side effects, auth, and confirmation, which is strong. It stops short of stating error/edge behavior (e.g. what happens if the class is full and waitlist is false), leaving a small gap.

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%, so names, descriptions, and defaults are already documented (including waitlist defaulting to false). The description restates the waitlist=true behavior but adds no new syntax or semantics beyond the schema, so the baseline of 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?

The description gives a specific verb+resource ('Book a customer into a class') plus the alternate path ('or add them to its waitlist'), which cleanly distinguishes it from siblings like momence_cancel_booking or momence_check_in_customer. An agent can identify the operation without opening the 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?

It covers operational usage (default confirmation per call, opt-out, confirm with the user since it reaches other people) but offers no explicit when-to-use-vs-alternative routing, e.g. when to prefer booking vs. a waitlist add versus other momence tools. Usage is implied through the waitlist condition and confirmation notes, not stated as selection guidance.

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