canvas_assignment_groups

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so safety is covered. The description adds behavior the annotations don't: the response carries per-group weights and drop rules, which is precisely the data needed for grade math. It omits any note about paging through large group lists despite the page parameter.

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?

Two sentences, zero filler, with the resource and its most decision-relevant fields front-loaded before the follow-up tool suggestion. Nothing repeats the schema or annotations.

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 listing tool with no output schema, the description usefully previews the returned fields (weights, drop rules) and the downstream workflow. The only material gap is pagination behavior, though the schema's page parameter and next_page pattern partially cover that.

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%, so course_id, page, and raw are all documented in the schema itself. The description adds nothing parameter-specific beyond implying course scoping, so the baseline of 3 is appropriate.

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?

Names a specific verb and resource ("List a course's assignment groups") and enumerates the payload an agent cares about: grade weights and drop lowest/highest rules. The Homework/Exams examples make the concept concrete and distinguish it from a plain assignments listing.

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 usage context — pair with canvas_course_submissions to compute a weighted grade — which tells the agent why to call it and what to call next. It stops short of explicit exclusions (e.g., use canvas_assignments instead when you want individual assignment rows), so it is clear context without full when-not guidance.

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