post_submission_comment

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

With no annotations, the description carries the transparency burden. It discloses the critical behavioral guarantee: 'without changing the grade,' which prevents misuse. It also implies a non-destructive, additive operation ('Add a comment'). It does not mention side effects like student notifications or overwrite behavior, but these are less central to a comment tool and the description covers the most important behavioral boundary.

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 three sentences that are all useful: the main action, a contextual use case, and an explicit alternative. It is front-loaded with the core purpose and contains no filler. Every sentence earns its place.

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?

The tool is a simple mutation with 5 well-documented parameters. The description provides purpose, usage context, and an alternative, which is sufficient for an agent to select and invoke it correctly. No output schema exists, but the description adequately covers the main concerns; missing details like student notification are not essential for basic use. Slightly more detail on the group_comment behavior could be added, but it's already in the schema.

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 the schema already documents every parameter (course_id, assignment_id, user_id, comment, group_comment). The description adds no parameter-specific detail beyond what the schema provides. It only offers general context for the tool's purpose, which does not enhance parameter understanding. Baseline 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?

The description opens with 'Add a comment to a student's submission without changing the grade', which clearly identifies the action (add comment), target (student's submission), and the key differentiator (no grade change). This distinguishes it from the sibling grade_submission tool, making the purpose unambiguous.

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?

It explicitly states when to use this tool: 'Useful for leaving feedback during review or asking for revisions.' It also names an alternative for a related need: 'For comments + grade in one call, use grade_submission with the comment field instead.' This provides clear when-to-use and when-not-to-use guidance.

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