canvas_create_calendar_event

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

With no annotations, the description carries the full burden and does well: it flags 'MUTATES the course' and discloses the important side effect that the event appears on every enrolled student's calendar. It does not cover permission/auth requirements or what happens if a course_id is invalid, so it is strong but not exhaustive.

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?

Front-loads the action and the mutation warning, then usage guidance, then a compact Args block. Every sentence earns its place, and the arg annotations are necessary given 0% schema coverage rather than redundant.

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?

An output schema exists so return values need not be explained, and the description still covers the mutation side effect, student-wide visibility, usage boundaries, and all parameter semantics. For a 6-param mutation tool with no annotations, nothing essential 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 description coverage is 0%, so the description must compensate, and it documents all six parameters: ISO 8601 UTC format with a concrete example for start_at, omitting end_at for a point-in-time event, HTML allowed in description, location meaning, and the CANVAS_DEFAULT_COURSE_ID default for course_id. This adds substantial meaning beyond the bare schema titles.

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 ('Create a calendar event on the course calendar') and immediately scopes it ('MUTATES the course'). It also carves out a boundary against a sibling concept by ruling out assignment due dates, letting an agent distinguish this from canvas_create_assignment 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 explicit when-to-use examples (class meetings, office hours, guest lectures) and an explicit when-not-to-use case pointing to the right alternative (assignment due dates belong on the assignment so the gradebook sees them). Both the positive and negative routing conditions are stated.

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