get_calendar_eventRetrieve a single Canvas calendar event by ID, including its full description. Use it to view event details; for assignment due dates, retrieve assignment details instead.
Get one calendar event in full, including its description.
| Name | Required | Description | Default |
|---|---|---|---|
| event_id | Yes | Numeric calendar event ID (from list_calendar_events). For an assignment due date, use get_assignment_details instead. |
Changes observed during successful MCP inspections.
v1.15.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds that the response is complete and includes the description field, which is mildly useful, but says nothing about permissions, error behavior when the event_id is invalid, or what 'in full' actually contains.
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?
A single short sentence with the key qualifier ('in full') front-loaded; nothing is padded and every clause carries information.
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 read tool with no output schema and readOnlyHint set, the definition covers what is needed to invoke it. The only gap is that 'in full' is never concretized into the fields returned.
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 100% and the schema's event_id text is richer than the description, including the string-or-integer type and the alternative tool for assignment due dates. The description adds no parameter meaning beyond that, so 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 specific verb and resource ('Get one calendar event') plus a scope qualifier ('in full, including its description'), which separates it from the list tool. It does not name list_calendar_events or any sibling in the description text itself.
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?
Use is only implied: retrieve a single event when you need the full record. The explicit 'from list_calendar_events' and 'use get_assignment_details instead' routing lives in the schema's parameter description, not in the description, so the agent must read the schema to get the guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.