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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds useful context about being the starting point for the task workflow, but says nothing about what a read-only list returns, ordering, or behavior when no lists exist. Adequate but thin beyond the annotations.

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 short sentences, zero waste, with the routing hint ('start here') front-loaded immediately after the purpose statement. Nothing could be cut without losing 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?

For a one-parameter read-only listing tool with annotations covering safety, the description plus schema is nearly self-sufficient, and the downstream listId dependency is called out. The only gap is that with no output schema, the agent isn't told what a list entry looks like (id/title), which matters given the stated dependency.

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?

One parameter with 100% schema description coverage; the mailbox field is fully documented in the schema including a pointer to list_authorized_mailboxes. The description adds no meaning beyond that, so the baseline of 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 ('List the user's Google Tasks lists'), which cleanly separates it from list_google_tasks (tasks inside a list) and list_outlook_task_lists (the Outlook equivalent) in the sibling set. An agent can pick it without opening either 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?

'Start here — every other task tool needs a listId' gives clear sequencing context and implies a prerequisite relationship with create_google_task/list_google_tasks. It stops short of naming those alternatives explicitly or stating exclusions, but the intended entry point is unambiguous.

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