Timetable

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

The description discloses a non-obvious side effect: selecting the week mutates the remembered week in the Librus session, which explains why readOnlyHint is false for a seemingly read-only tool. That is exactly the kind of context annotations cannot convey, though it could go further on the durability or risk of that session change.

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?

Two tight sentences with zero filler; the core purpose is front-loaded and the side-effect caveat follows immediately. Every clause carries information.

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 an output schema present and full schema coverage, the description need not explain return values, and it covers the main behavioral surprise (session week change). Minor gap: no mention of ordering/which week is default or how ambiguous weeks are handled, but nothing critical is missing.

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 both parameters (monday, account_alias) are already documented in the schema. The description reinforces the temporal semantics ('one week', 'school local time') but adds no format or edge-case detail beyond the schema, 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?

States a specific verb and resource ('Get the lesson plan for one week') and adds scope detail: substitutions, cancellations, and school local time. It is clear what the tool returns, but it does not explicitly distinguish itself from nearby siblings like get_agenda or get_completed_lessons.

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 rather than stated: the agent can infer 'use this for a single week's lessons' from the week parameter, but there is no explicit when-to-use versus get_agenda/get_homework guidance and no prerequisites mentioned (e.g., that account_alias comes from list_accounts).

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