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

Annotations already declare destructive=true, idempotent=false, and openWorld=true, but the description adds cost and side-effect detail the annotations cannot convey: it spends one autopilot credit (or a Plus subscription slot), mails the guests, requires the send permission, and cannot be undone. That is exactly the extra context an agent needs before a costly, irreversible action.

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 verb and resource, then packed with cost, permission, and irreversibility in one dense em-dash sentence. Every clause carries information, though the single run-on sentence is slightly heavy for the amount of content.

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?

An output schema exists, so return values need not be explained. The description covers the input's provenance, the credit/subscription cost, the required permission, and the irreversibility — everything an agent needs to decide and act safely.

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% for the single draft_id parameter, and the schema already says it is the draft_id create_event returned. The description restates the same provenance without adding format, validation, or lookup guidance, so it sits at the baseline for a fully documented single parameter.

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 ('Sends a draft's invites') and immediately disambiguates with parenthetical detail ('mails the guests, spends one credit') plus an equivalence claim ('the exact Send the draft's own review page runs'). It also anchors the input to a sibling ('a draft_id from create_event'), so an agent can separate this from confirm, discard_draft, or get_draft without opening another schema.

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 clear context for when this applies: only for a draft_id that create_event produced, and it is the same action as the draft's review page Send. No explicit when-not or named alternative (e.g., discard_draft for abandoning a draft) is offered, so it is clear context without exclusions.

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