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

Annotations already declare destructive, idempotent, and open-world behavior, so the description's job is lighter: it adds the approval model (agents may confirm without per-step human approval), the precondition that confirmation requires a proposed date, and the human veto path. That is meaningful context beyond the annotations, though it says nothing about what a destructive update overwrites.

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 editable fields are front-loaded in the first sentence and the approval rules follow. It is dense but nearly every clause carries information; the only softness is the compressed phrasing around 'coordinate alternatives,' which is more workflow narrative than invocation guidance.

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 destructive, idempotent mutation with 10 parameters at 0% schema coverage and no output schema, the description covers the approval and veto semantics well but omits the identities required to call it (eventId, participantId, requestId) and what a destructive update affects. Adequate for the workflow, incomplete for invocation.

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 0% across 10 parameters, so the description must compensate. It covers title, description, timezone, location, and status, and implicitly ties confirmedDateId to confirmation, but leaves eventId, participantId, requestId, and agent entirely unexplained, so half the surface remains undocumented.

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?

The first sentence gives a concrete verb plus the exact editable fields (title, description, timezone, location, status), which clearly separates it from siblings like propose_date or create_event. It does not explicitly name which sibling handles non-update flows, but 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?

The description gives workflow guidance for two cases: agents confirming a proposed plan without per-step approval, and humans vetoing by setting status to planning and re-coordinating. It never states when to use update_event instead of propose_date, remove_date, or create_event, so routing to alternatives is left implicit.

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