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

Goes well beyond the annotations by disclosing the two-step confirmation mechanism, that the merchant (not the agent) is the confirming party, and the money-as-integer-minor-units convention. There is mild tension with readOnlyHint=false and idempotentHint=false, but 'changes nothing' is scoped to the plugin's settings, while the call still emits a preview/confirmation artifact - so this reads as a clarification, not a contradiction.

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?

Four short sentences, each doing distinct work: purpose, unit convention, behaviour of the call, and who authorises the change. The most decision-critical fact (it changes nothing) is front-loaded after the purpose line, with 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?

With no output schema, the description correctly picks up the burden of describing the response ('a preview of what would change and a confirmation link'), and it covers the nested values object indirectly by deferring key names to plugins.list. The preview payload's shape is still only sketched, which keeps this just short of full completeness.

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 already 100%, so the baseline is 3. The description adds genuinely new information the schema lacks: monetary number fields are in integer minor units (cents). That is a unit semantic the schema does not state, which is exactly the kind of addition that earns a point above baseline.

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?

The opening sentence gives a specific verb+resource ('Change a plugin's settings'), and the following sentences refine that into a preview/confirmation flow rather than a direct write. It implicitly distinguishes itself from plugins_list (read), plugins_set_enabled (enable/disable), and the store-wide settings_* siblings, but never names an alternative explicitly.

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?

It supplies real usage context: the call is non-committal and completion requires the merchant to act on the confirmation page. That tells the agent not to expect the change to apply after the call. However, there is no explicit 'use this vs. settings_checkout / plugins_set_enabled instead' routing.

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