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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, and the description adds real context beyond them: private-event invisibility, the meaning of the `found` flag, and an instruction to relay any returned note verbatim because it asks the user to connect their own calendar. The trailing paragraph about writing a from/to range with a UTC offset from well_convert_time is boilerplate that does not fit a single-event read and slightly muddies the behavioral picture.

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?

Core capability and usage triggers are correctly front-loaded, but the long parenthetical on birthday_in_days and the closing 'Read the calendar. Write the from and to of a range...' paragraph dilute focus and read as copied boilerplate. Some sentences restate what the schema already documents at full coverage.

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 read-only single-record tool with an output schema present, the description covers the gaps that matter: visibility/missing-event behavior, repeating-instance selection, and workspace selection. It does not touch conversation_id or workspace_scope, but the schema documents both at high coverage, so nothing an agent needs to invoke the tool correctly is missing.

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; the description goes further by explaining that occurrence_start must come from well_list_calendar_events to read one instance of a repeating event, and by restating the workspace_id conditional so the agent knows when omission is safe versus wrong. It also explains the guest-level birthday_in_days sign convention, which the schema alone would not convey.

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?

Opens with a specific verb and resource ('Read one calendar event') and immediately delimits what comes back: full description, guest list with per-guest fields, and saved notes. It is clearly distinct from well_list_calendar_events, which it names, so an agent can choose between the single-read and list tools without opening either 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?

Gives concrete triggers ('who is invited to a meeting, what the agenda says, what they noted about a meeting, or before changing an event') and routes to the sibling that supplies an id. It also states the exclusion rule that an event kept private by another member is not found, and spells out the workspace_id condition for single- vs multi-workspace tokens.

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