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

Annotations only supply readOnly=false, destructive=false, openWorld=true. The description adds real behavioral context beyond them: no invitation is dispatched, the draft is invisible to recipients, it is editable afterward, no payment occurs, and a Cotlet API key scoped to this app is required.

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?

Front-loaded with the core action and the critical 'nothing is sent' constraint early. Slightly redundant — the opening line and the third sentence both restate that it builds a draft from a gallery design — so it is efficient but not maximally tight.

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?

Covers safety profile, prerequisites (API key), and next-step tools, which is strong for a mutation tool with no output schema. The one gap is that it never indicates what the call yields — presumably an event identifier the agent needs before calling update_event or send_invitation.

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 the schema already describes every one of the 7 params, including 'Free design from the Evite gallery.' The description reinforces the free-design constraint and mentions 'Event Details' filling, but adds no format or interaction detail beyond the schema, 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+resource ('Creates a draft' event) and immediately delimits scope: 'Nothing is sent until send_invitation.' It also names the sibling that mutates the same object (update_event) and the one that actually dispatches (send_invitation), so an agent can separate it from evite_send_invitation without opening schemas.

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?

Explicit when-to-use framing — the draft 'reaches no one' and 'runs without asking' — plus named alternatives for the next step (update_event, send_invitation). It even clarifies that premium design purchases happen in Evite, not through this tool, which prevents a mistaken call.

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