list_grading_periods

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

With no annotations provided, the description carries the full burden. It discloses the exact fields returned (id, title, start_date, end_date, is_closed) and the behavior for schools without grading periods (a single default period). It also explains how the IDs can be used downstream. It could mention error cases or ordering, but for a simple list operation, this is strong transparency.

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?

The description is concise (three sentences) and well-structured: purpose, return fields, and usage guidance are clearly front-loaded. Every sentence adds value with no repetition or filler.

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 single-parameter list tool with no output schema, the description is remarkably complete. It explains the return format, an edge case (default period), and how the results are meant to be used in the broader grading context, leaving no significant gaps for the agent.

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?

Only one parameter exists, and the schema already describes it as 'Canvas course ID' with 100% coverage. The description adds minimal additional semantics beyond 'a course's term', so the baseline of 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?

The description uses a specific verb ('List') and names the resource ('grading periods') with clear scoping to 'a course's term'. It differentiates from sibling tools like list_calendar_events and list_terms by focusing solely on grading periods and even explains their purpose in the grading workflow.

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?

The description clearly states when to use this tool: to obtain grading_period_id values for scoping grades/submissions to a single period, as opposed to using the cumulative lifetime grade. It also provides the important caveat about schools without grading periods. However, it does not explicitly discuss alternative tools or when not to use it, so it falls short of a 5.

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