create_reminder_list

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

Beyond the readOnlyHint=false annotation, it discloses the mutation side effect explicitly, the exact-name uniqueness rule and why it exists, the return payload (pointer with id and name), and the EventKit permission requirement. That is the full behavioral profile an agent needs.

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?

Three short sentences, front-loaded with the action, then the constraint, then the return value and permission note. No filler.

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 single-parameter creation tool with an output schema already present, the description covers creation scope, duplicate behavior, return shape, and auth dependency. Nothing needed to invoke it correctly 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?

Only one parameter and the schema coverage is 0%, so the description must carry the load; it conveys that the name must be unique and that the returned id is what later tools expect, but it says nothing about naming format, length, or case sensitivity of the duplicate check.

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 ('Create a reminder list') plus the scope ('in the default Reminders account'), which cleanly separates it from create_reminder (a reminder, not a list) and from reminder_lists (read-only listing).

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?

Tells the agent what to do with the result ('use the id as `list_name=`'), which is real chaining guidance, and flags the duplicate-name precondition. It never names an alternative tool or an explicit when-not, so it stops short of a 5.

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