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

Annotations already declare idempotentHint=true and destructiveHint=true; the description reinforces both and adds real operational context: an immediate Cycle starts, startedCycleId reports it and is absent when nothing started, and Cycles burn Fuel unless the plan covers them. What's missing is any warning about the cost/irreversibility of the immediate Cycle beyond 'burns Fuel'.

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?

Effect is front-loaded in the first sentence, then costs, guards, and idempotency in a logical order. The startedCycleId sentence is long and comma-chained, packing three absence reasons into one clause, which slightly hurts readability.

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?

There is no output schema, and the description usefully documents the returned startedCycleId and when it is absent, which an agent otherwise could not infer. The remaining gap is identifier semantics, though for a two-id mutation tool this is minor.

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 description coverage is 0%, so the description carries the full burden, yet it never explains projectId or monitorId (e.g., whether projectId is the Monitor's owning project or how to obtain monitorId). Only the parameter names imply meaning.

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?

Specific verb (Enable) plus resource (Monitor) with a precise statement of effect: Cycles run on their schedule and a Cycle starts at once. It is clearly distinguishable from siblings disable_monitor, update_monitor, and create_monitor.

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?

Explicit preconditions ('Enable only after the user confirms in this conversation'), explicit refusal case (unclaimed Trial), explicit idempotent no-op case, and the counterpart tool (disable_monitor) is named as the way to reverse it. It also routes to get_documentation topic 'faqs/plan-or-fuel' for cost questions.

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