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

Goes well beyond the annotations by enumerating exactly what is copied (title, description, location, theme, questionnaire, RSVP settings) and what is not (guests, messages, RSVP deadline), notes 'Nobody is invited', states the auth constraint ('Hosts only'), and discloses the return value ('Returns the new event').

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 scoped detail after, with no padding; however 'The copy has no guests yet' and 'no guests and no messages' restate the same fact in adjacent sentences.

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 write tool with no output schema, the definition covers copy semantics, permissions, non-invitation behavior, and the return value well; it is only missing an explicit statement of what the source event's state is after the call.

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 baseline is 3, but the description adds real semantics beyond the schema: the copy 'starts at start_at and keeps the original's length', clarifying that the end time is derived rather than supplied.

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 ('Copy an event ... to a new date') and immediately distinguishes it from create_event by equating it to the event-page 'Duplicate' action, so the agent knows it clones settings rather than starting fresh.

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?

Usage is only implied: 'Hosts only' gives a permission precondition and the Duplicate analogy hints at the scenario, but no sibling (create_event, update_event) is named as an alternative, and no explicit when-not-to-use case is given.

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