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

The description adds useful behavioral context beyond the annotations: it replaces today's list, empty array means everyone is present, absent children disappear from name widgets today, and the day is retained in the class absence list for one year. This is strong disclosure for a mutation tool, though permissions and error behavior are not covered.

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, stating the operation first and then adding replacement semantics and consequences. The parenthetical empty-list rule is efficient and no sentence is wasted.

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 three-parameter mutation tool with annotations and no output schema, the description covers the key effects: replacement, widget visibility, and absence-list retention. It is nearly complete, missing only guidance on class vs. class_id selection and failure behavior.

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 67%, with class and absent documented in the schema but class_id undocumented. The description clarifies the meaning of an empty absent list and ties the operation to a class, but it does not explain the class vs. class_id alternative or add much beyond the existing parameter descriptions.

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: setting which children in a class are absent today. It also implicitly distinguishes itself from list_absences by describing a mutation that replaces today's list, so an agent can identify the operation without opening the schema.

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?

Usage is implied through 'heute fehlen' and 'ersetzt die Liste für heute', making clear this updates today's attendance. However, it does not state when not to use it or explicitly name alternatives such as list_absences.

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