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

Annotations already declare this is a non-read-only, non-idempotent mutation, so the safety profile is covered. The description adds real behavioral value beyond that: the expiry-if-ignored outcome, the no-justification policy for declining, and where incoming invitations originate.

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 short sentences, each carrying distinct information, with the core action front-loaded before the supporting details about discovery and expiry. No filler.

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?

There is no output schema, and the description adequately frames the decision space and the ignore-instead option. It stops short of saying what accepting actually triggers (e.g., an interaction the agent may later need to leave via vacation_leave_interaction), a small gap for a mutation 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?

Schema description coverage is 67%: token and decision are well-documented in the schema, but interactionId carries only a format hint. The description reinforces the decision values and indirectly points to where the interactionId comes from (look_around/events), which is a modest addition over the schema.

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 pair (accept/decline) and the exact resource (an invitation somebody sent you), which an agent can immediately distinguish from sibling write tools like vacation_invite_to or vacation_leave_interaction. The scope is unambiguous.

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?

Explicitly covers when to act (pending invitations surface in look_around and arrive as interaction_proposed events), how to decide (declining is fine, no justification needed), and the third option of doing nothing since the invitation expires. When/when-not/context is all there.

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