list_task_lists

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavior beyond that: it returns all task lists for the current user, includes write access status, and documents the exact fields in the result. No behavioral contradictions or hidden side effects are present.

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 front-loaded with the core purpose and stays compact overall. There is minor redundancy between 'including name, color, supported component types, and write access status' and the later explicit field list, but the duplication is harmless and the structure remains scannable.

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?

Given that the tool has no parameters and an output schema exists, the description is complete enough for correct invocation. It states what the tool lists, the fields returned, and how to use the id downstream. No missing prerequisites, side effects, or special cases are necessary for this read-only enumeration 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?

The tool has zero parameters, so the baseline is 4 because there is no parameter semantics for the description to clarify. The description focuses instead on the output structure and usage of the returned id, which is the only semantically relevant information an agent needs.

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 opens with a specific verb and resource: 'List all task lists (CalDAV calendars with VTODO support) for the current user.' It clearly defines scope by naming VTODO support, distinguishing task lists from plain calendars. It also states the return object's purpose, so an agent knows exactly what this tool produces.

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 gives clear context: use it to enumerate the current user's task lists, and then pass the returned id to other task tools such as 'tasks'. It does not explicitly name alternatives like list_calendars or say when not to use it, but the VTODO-specific definition makes the intended scenario unambiguous.

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