add_class_students

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

With no annotations, the description carries the full behavioral burden. It discloses the required permission (PS_ENABLE_WRITES), the serialized nature of writes and the need to avoid parallelism, idempotency (re-running safe, skipping existing students), and that it does not disturb existing class memberships. This is exceptionally transparent.

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 longer than a single sentence but well-structured: purpose/requirement, SAFETY callout, behavior notes, and usage example, then an Args section. Every sentence carries meaning, and key information is front-loaded. Slightly verbose but not 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?

The description covers permissions, safety, idempotency, example usage, and parameter details. It does not describe the return value, but an output schema exists (context says has output schema: true), so that gap is acceptable. For a write tool with no annotations, this is sufficiently complete.

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 has 0% description coverage, so the description fully compensates. It explains each parameter's meaning and origin: section_id from list_classes, student_ids from list_students. This adds critical context (that these are IDs from other tools) that the schema's bare 'integer' and 'array' types do not provide.

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 action ('Enroll students in a class') and clearly differentiates it from sibling tools like remove_class_students and move_student_to_class. The description further clarifies it adds everyone in a single call without disturbing existing enrollments, making the scope 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?

Provides explicit guidance: gives a concrete use case ('assign a whole grade at the start of the year') with a workflow referencing list_students(grade=...), and warns against parallel calls, recommending a fresh read after. This is clear when-to-use and how-to-use guidance, and it distinguishes from alternatives implicitly.

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