Class teachers

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds the meaningful caveat that email addresses only appear when Classroom shares them, and that results are grouped per class rather than flattened. It does not mention pagination or result ordering, though the schema's offset field covers paging.

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 paragraph is front-loaded with what is returned, then how to scope the call, then when to reach for it, with no filler sentences. The quoted user phrasings are slightly verbose but earn their place as selection cues.

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?

With no output schema, the description carries the burden of describing returns and does so (per-class lists, email addresses conditionally included). Selection semantics, defaults, and the sharing caveat together are sufficient for a read-only four-parameter lookup tool.

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 coverage is 100%, so the baseline is 3, and the description adds genuine relationship semantics: course_id targets one class while course_ids/course_name target many, and an empty selection means all active classes. It does not, however, explain how course_name matches are resolved beyond what the schema already states.

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 opening clause names a specific resource (teachers of your classes) and the payload (email addresses, when Classroom shares them), which distinguishes it from sibling list tools such as get_my_courses or get_assignments. An agent can tell immediately that this returns instructor identities rather than course metadata.

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 covers all three selection modes (course_id for a single class, course_ids or course_name for several, and no argument for all active classes) and adds concrete user phrasings ('Who teaches this class?', 'How do I email my teacher?') that trigger the tool. Exclusion conditions are implicit in the mode breakdown, but the routing instruction for course_name versus get_my_courses is explicit.

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