Accept or decline an invitation

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

Discloses important behavior that annotations do not capture: an unsendable reply to the organizer, a confirmation step before sending, scope limited to the caller's own attendee line, and a server-level constraint on attendee manipulation. This goes well beyond readOnlyHint/destructiveHint/idempotentHint and helps the agent predict side effects.

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?

Four concise sentences, each serving a purpose: the primary action, the irreversible side effect and confirmation behavior, the scope boundary, and a relevant server limitation. The most important information is front-loaded and there is no redundant or promotional language.

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?

Given the output schema exists, return values need not be explained. The description covers purpose, side effects, scope, confirmation behavior, and a server constraint. The only subtlety, the confirm_token flow, is already described sufficiently in the schema as 'Token from the first call of this tool.'

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?

The input schema has 100% parameter description coverage, so the baseline is 3. The description adds little direct parameter-level meaning beyond the schema, though 'so it asks first' helps contextualize confirm_token. This is acceptable because the schema already documents id and confirm_token clearly.

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 action ('Sets your own participation status on an event'), names the resource type, and clearly distinguishes itself from attendee management tools by saying it never modifies anyone else's attendee line and that this server cannot add or remove attendees at all. The title 'Accept or decline an invitation' reinforces the purpose.

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?

Clearly establishes when to use the tool: for the caller's own response to an invitation. It also gives an explicit when-not by stating it does not affect other attendees and cannot add or remove attendees. It does not name a specific sibling alternative tool, but it gives enough context to avoid misuse.

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