canvas_create_assignment

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

With no annotations, the description carries the full burden and does: it declares the write/mutation, the default-unpublished visibility state, the UTC storage caveat that makes naive local deadlines wrong, and the default values for grading_type, submission_types and course_id. That is exactly the behavioral context an agent needs before calling.

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 purpose and the mutation/visibility warning before the Args block, then keeps one tight line per parameter. The timezone note is long but earns its place by preventing a concrete, common error.

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?

A 12-parameter mutation tool with an output schema present, so return values need not be explained. Everything else an agent needs — mutation semantics, visibility default, date format, enum values, course scoping — is covered.

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 does, documenting all 12 parameters including the enumerated values for submission_types and grading_type, the ISO 8601 UTC format with a worked example, and the semantics of omit_from_final_grade and points_possible (omit for ungraded).

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+resource ("Create an assignment") and immediately flags the mutation ("MUTATES the course"), which cleanly separates it from canvas_update_assignment and the read-only siblings. An agent can pick this tool without opening the 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 a clear conditional rule for the risky flag: default unpublished, pass published=True only when the instructor confirms readiness. It also routes the agent to canvas_list_assignment_groups for the group id. It stops short of naming when to prefer canvas_update_assignment or listing prerequisites, so it is strong but not exhaustive.

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