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

Beyond the annotations, it discloses that changed events keep their identity and receive a higher revision so subscriber apps refresh, that cancelled events remain visible as cancelled, and that no one is notified. That is substantive side-effect context an agent cannot infer from destructiveHint/openWorldHint alone, and it does not contradict them.

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?

Three sentences, front-loaded with the trigger and operation list, followed by prerequisites and then side effects. No filler, and the negative constraints are placed last where they read as caveats.

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 multi-operation mutation tool with an output schema, the description covers operations, prerequisites, and side effects well. It stops short of saying what happens when an event number is invalid or when a batch partially fails, which would matter for a 50-item changes array.

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%, so the baseline is 3, but the description adds provenance the schema lacks: the manage_link is the private organizer link and event numbers must come from show_group_calendar. It does not add format or interaction detail for the nested change/add arrays, which the schema already documents thoroughly.

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 description names a specific verb and resource and then enumerates the exact operations covered: adding events, changing time/date/place/note/repeat/skipped dates, cancelling, restoring, and renaming. It also distinguishes itself from the sibling show_group_calendar by pointing there for event numbers, so an agent can route correctly without opening a 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?

It opens with an explicit trigger ('Use this when the organizer wants to...') and lists the concrete situations that select this tool. It also states prerequisites (private organizer link, event numbers from show_group_calendar) and two exclusions (does not notify, does not delete), which is exactly the when/when-not guidance the dimension asks for.

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