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

Adds real context beyond the annotations: the action is agent-restricted and one-way from the agent's side, which tells the agent not to attempt a compensating re-enable. Annotations already cover safety (destructiveHint=false, idempotentHint=true), so the description only needs to add state/permission nuance, which it does. It stops short of saying what preconditions exist (e.g., auto-recharge already off) or how failure surfaces.

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, the action front-loaded and the permission constraint second. Every clause carries information an agent needs; nothing is padded.

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 zero-param mutation with an output schema and full annotations, the description covers purpose, direction, and the agent's authority limit — enough to call it correctly. Minor gap: no note on what state or error appears if auto-recharge is already disabled, though idempotentHint implies that case is benign.

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?

Zero input parameters; schema coverage is 100% and there is nothing to document. Baseline for a no-param tool 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+resource pair ('Turn automatic top-ups off') that maps one-to-one with the tool name and cannot be confused with a read or a generic update. The second sentence makes the direction explicit, distinguishing it from any hypothetical enable operation.

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?

Explicitly states the boundary condition: an agent may only disable, never enable, and names the alternative path (the owner enabling it on the account page). No sibling tool overlaps this capability, so no further routing is needed.

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