Attach Material to Submission

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

The description discloses the mutating nature, the required before-turn-in state, the one-of constraint, and the return confirmation. This goes beyond the annotations, which already indicate a non-read-only, non-idempotent, non-destructive operation; no contradiction exists.

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 compact and front-loaded with the most important guidance ('BEFORE turning it in'), followed by a clear argument list and return note. Every sentence adds value without redundancy.

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 tool with no schema-declared parameters and no output schema, the description covers all necessary invocation details: required IDs, optional attachment selection, the one-of requirement, sequencing, and the return confirmation.

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?

Although the input schema is empty, the description manually documents all five parameters with types, optionality, and the exactly-one constraint. This fully compensates for the missing schema information and directly guides the agent on what to 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?

The description states a specific verb and resource: 'Attach a Drive file or link to a student submission'. It also distinguishes itself from the sibling classroom_turn_in_submission by emphasizing the BEFORE turning it in ordering.

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 explicitly instructs to add attachments first and then call classroom_turn_in_submission, giving clear sequencing and naming the sibling alternative. It also clarifies that exactly one of drive_file_id or link_url must be provided.

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