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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds valuable behavioral detail beyond that: guests are NOT copied, nothing is sent so there's no confirmation, and it requires a Cotlet API key with app access. The main omission is whether the copy lands in draft/unpublished state.

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 sentence is front-loaded and clear, but the description restates the same idea twice — 'Copy an event with its settings to a new date' then 'Does what Clone Event does... copies the event details to a new event on the date you give.' That redundancy costs it a point.

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, the description covers the key side effects (no guests, no notifications, auth requirement) but does not say what is returned or how to obtain the new event's ID, which is important for a duplicate-and-then-invite workflow.

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 event_id and start_at are fully documented in the schema. The description's phrase 'on the date you give' only loosely reinforces start_at and adds no syntax or format detail beyond the ISO 8601 schema note. 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 (copy/duplicate) and resource (event) with clear scope: settings carried over, new date required, guests excluded. An agent can distinguish it from partiful_create_event and partiful_update_event 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?

It names invite_guests as the follow-up for re-inviting guests and clarifies that no confirmation is sent, which is useful context. However, it never states when to prefer this over partiful_create_event versus manually recreating an event; usage is only implied by the 'Clone Event' analogy.

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