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

Adds meaningful context beyond the annotations: partial-update semantics ('only the fields you pass change'), a default confirmation requirement that can be toggled off, the side effect of reaching other people, and an explicit auth requirement (Cotlet API key with app access). openWorldHint=true already signals external reach, but the confirmation and auth details are genuinely extra. No contradiction with destructiveHint=false.

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 field list is repeated across the first two sentences with a small inconsistency ('date' vs 'name'), which is avoidable duplication. The behavioral notes that follow are useful and front-loaded reasonably, but the opening redundancy dilutes efficiency.

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 2-param mutation with no output schema, this covers partial-update behavior, notification responsibility, confirmation policy, and auth. The only notable gap is the expected return/confirmation response, which is minor since failure modes are not enumerated.

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 event_id and the fields payload are already documented in the schema. The description restates the same field list rather than adding format or syntax detail. 'Only the fields you pass change' adds a small semantic note, so 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 (change an event) and enumerates the mutated fields (date/times, venue, line-up, description). An agent can tell it apart from dice_cancel_event, dice_update_ticket_type, or dice_create_event. It stops short of naming a sibling to avoid, so it is clear but not sibling-differentiated to a 5 standard.

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 routing guidance: fans may already hold tickets, so notify them with 'message_attendees'. It also establishes a per-call confirmation posture. It lacks an explicit 'when not to use this / use X instead' for update alternatives (e.g., cancel_event), keeping it just under 5.

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