Set a task to ring

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

With no annotations, the description carries the full disclosure burden and does it well: it states the operation is purely additive ("never takes one away"), reassures that user-set reminders survive, and points at `read` as the way to inspect existing reminders first. It doesn't cover idempotency for duplicate times or what the call returns on conflict.

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 core action, then the safety guarantee, then the usage rule. The final clause is slightly elliptical but each sentence carries distinct 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 two-parameter mutation tool with no annotations and no output schema, the description covers mutation semantics, reversibility/safety, and the read-before-write pattern. A note on duplicate handling or the response shape would close the remaining gap.

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 the schema already explains both `task` (task id) and `at` (array of day+hour timestamps). The description adds no format or constraint detail beyond what the schema states, 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 concrete verb and resource ("Make a task... ring at a given moment") and scopes it to tasks that already exist, which separates it from creation-style siblings like plan or propose. It stops short of naming a specific alternative tool it should not be confused with.

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 a positive case ("the appointment that was filed without one") and an explicit exclusion ("leave alone what repeats — a routine already comes back on its own"). Clear context, but it references siblings only obliquely via `read` rather than by tool name for the add-vs-modify decision.

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