Schedule

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds real value on top: the 42-day cap, the default window, the guarantee that every day has an items array (empty on free days), and the filtering rule that routine 'Inschrijving in orde.' notices are dropped while real warnings are kept. That filtering surprise is exactly the kind of behavior an agent could not infer elsewhere.

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?

Front-loaded with the resource, followed by the field inventory, then the two operating constraints (default window, maximum). Dense but every clause carries information an agent would otherwise have to discover empirically.

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 return-shape burden and does so thoroughly for a read-only query tool. The only remaining gap is its relationship to the `lessons` sibling and any ordering/pagination 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 100% and each parameter already carries a description, including the Amsterdam timezone for `date` and the multi-child requirement for `leerlingId`. The description adds only the default range values, which is a modest supplement, so the baseline 3 applies.

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?

Names a specific resource (timetable) with an explicit enumeration of what each day contains (lessons, tests, appointments, changes, cancellations, attachments, holidays). It is clearly distinct from grades/messages siblings, but the overlap with the `lessons` sibling is never addressed, so an agent cannot tell from this text alone which one to pick.

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?

Gives concrete operational context: defaults to today plus 6 days, and a hard maximum of 42 days. However, it offers no guidance on when to prefer this over `lessons`, `homework`, or `parent_evening`, and no stated exclusions.

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