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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=false), so the bar is lower; the description adds real context beyond them — the event is private to the member, exactly one event is created, and the reply should be read back to the member. It does not explain that repeated calls create duplicates (idempotentHint=false) or what the destructive hint means for a pure-add operation, which are the remaining gaps.

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?

Well front-loaded: the trigger conditions come first, then behavior, then defaults, then alternatives. The quoted example phrases are bulky but functional; the description runs long for a four-parameter tool, though each sentence carries routing or behavioral weight.

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?

There is no output schema, and the description compensates by describing what the reply contains and instructing the agent to say it back. Combined with the privacy scope, the defaults, and explicit sibling routing, an agent has everything needed to invoke this correctly.

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 title, starts_at, ends_at and all_day are already documented with defaults and format. The description restates the same facts (UTC offset example, one-hour default, all_day meaning) rather than adding new semantics, so the baseline 3 applies.

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 precise verb+resource ('Creates ONE event on the member's own Connections calendar') and immediately delimits scope as the private, member-only calendar. It also names the two nearest siblings it is not (connections_event_create, connections_todo_add), so an agent can disambiguate without opening any 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?

The opening sentence enumerates the triggering phrasings ('add it to my calendar', 'block out 2-4pm tomorrow') and the closing sentence gives explicit when-not routing: public event with page/tickets/RSVPs → connections_event_create, to-do with no time slot → connections_todo_add. Both the selection and exclusion conditions are stated.

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