Update event

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

Goes well beyond the annotations by disclosing PATCH semantics (omitted fields keep values, empty call refused), side effects (Guest Approval clears max_guests and the waitlist; a guest limit enables the waitlist), questionnaire replacement scope, and the return value. This is the kind of cross-field behavior an agent could not infer from readOnlyHint/idempotentHint alone.

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?

Purpose is front-loaded in the first sentence and every subsequent sentence carries information. The middle field-list sentence is dense and runs long, which costs a point but not readability.

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 states what is returned (the event, with updated fields) and covers side effects, refusal behavior, and authorization. An agent has everything needed to call it correctly.

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 the baseline is 3; the description earns above that by explaining interactions the schema does not (guest_approval clears max_guests, max_guests turns on the waitlist, questions replace the questionnaire for future RSVPs). It stops short of covering null semantics for max_guests explicitly in prose, though the schema handles that.

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?

Specific verb (change details/settings) plus concrete resource (an event you host), with an explicit field inventory that separates it from create_event, cancel_event, and get_event.

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?

Establishes the precondition 'event you host' and anchors partial-update behavior to the event's Edit page, making it clear this is for edits rather than creation or reads. It does not explicitly name sibling alternatives or when to prefer get_event first, so it stops short of a 5.

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