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

Annotations already declare destructiveHint=true, idempotentHint=true, readOnlyHint=false, so the safety profile is covered. The description adds a genuine pre-condition beyond the annotations: only records of type EVENT are deletable, which determines whether the call will succeed or fail — useful behavioral context. It does not say what happens to recurring events (single instance vs. series), which would have made it richer.

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?

Two tight sentences with zero filler. The positive operation is front-loaded and the scope restriction follows immediately, matching the order an agent needs to evaluate before calling.

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 and full annotation coverage, the definition supplies the key scoping rule and the valid source of the ID. It leaves minor gaps around recurring-event behavior and confirmation/undo semantics, but nothing that would cause an incorrect invocation of the documented happy path.

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%, and the single parameter is already documented as 'Event ID (from list_calendar, type EVENT)'. The description's parenthetical repeats that provenance rather than adding new meaning, so the baseline 3 applies — the schema does the heavy lifting.

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 a calendar event') and immediately narrows the scope to type EVENT. The second sentence lists what is explicitly out of scope (tasks, invoices, projects, expenses), which lets an agent distinguish this from the delete_task / delete_invoice / delete_project siblings without opening their schemas.

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 exclusion guidance — calendar entries that are tasks, invoices, projects, or expenses must be deleted elsewhere — which is the main misuse risk for this tool. It stops short of naming the concrete alternative tools (delete_task, delete_invoice), so the agent must infer the routing, but the when-not-to-use condition is explicit.

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