GroupClassPupilsAdd

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

Beyond the mutation implied by readOnlyHint=false, the description discloses a significant side effect: the pupil is activated and consumes the school's tariff quota. It also states the exact failure mode with HTTP 400 and the error message, giving the agent valuable behavioral expectations.

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?

Four short, purposeful sentences front-load the core operation and then explain side effects and error behavior. There is minimal redundancy and no filler, making the description easy for an agent to parse quickly.

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 mutation tool with no output schema, it covers the action, the key side effect, the dependency on the school's tariff plan, and the failure response. It does not describe the success return value or repeated-add behavior, but the annotations and schema cover the remaining essential invocation details.

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?

Input schema coverage is 100%, so the schema already documents both parameters, setting the baseline at 3. The description adds real-world meaning about the activation consequence but does not clarify whether bodyPupilIds may be omitted or how IDs are validated, so it does not rise above the baseline.

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 first sentence states a specific verb ('Add'), resource ('pupils'), and target ('group class'), clearly differentiating it from sibling tools like MarathonAddMarathonNewStudents or AccessGroupsAddMembers. It also adds unique behavioral context about activation and tariff consumption, going beyond the tool name.

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 frames when this tool applies: adding pupils to a group class, and it surfaces the tariff-limit implication that agents should consider before calling. It does not explicitly name alternatives or when-not conditions, so it stops 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.