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

Goes well beyond the annotations: destructiveHint only says the operation mutates, while the description discloses the two-step proposal protocol, that the tool never writes directly, and the exact response shape (status='confirmation_required' with action_id and plan_token). That is the precise behavioral context an agent needs to avoid assuming the delete already happened.

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?

The purpose and scope are front-loaded and the confirmation protocol is stated early. It is slightly repetitive — 'runs only after you confirm via confirm_action' is restated as 'PROPOSED, never performed directly' — but the repetition reinforces a safety-critical behavior rather than wasting space.

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 one-parameter destructive tool with no output schema, the description covers the mutation semantics and the confirmation handshake completely, which is the main risk area. Minor gaps remain: what happens when the id is unknown or the event is not the caller's, and no id-format guidance.

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 single parameter has 0% schema description coverage and is typed as integer-or-string union, which the description does not explain. 'By id' plus the caller-ownership restriction adds some meaning, but the id format and the union type remain undocumented in both places.

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 ('Delete one of the caller's calendar events by id') and adds a scope constraint ('Only the caller's own event is reachable'), which separates it from broader delete operations. It does not explicitly name a sibling such as delete_events for bulk removal, so differentiation is scoped rather than sibling-routed.

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?

Makes the usage context explicit: this is only for the caller's own event, and it must be followed by confirm_action for the write to occur. That is clear when-to-use and next-step guidance, though there is no explicit when-not (e.g., bulk-delete or other users' events) beyond the reachability note.

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