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

Adds substantial context beyond annotations: calling it is non-mutating (returns a preview plus confirmation link) and the final change requires merchant action on a separate page. This is exactly the 'what actually happens / what gets destroyed' information annotations alone can't convey. Minor tension with readOnlyHint=false and idempotentHint=false, but that reads as conservative endpoint classification rather than 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?

The behavioral sentences are tight and front-loaded, but the sentence 'Money is integer minor units (cents).' is irrelevant boilerplate for a language-setting tool with no monetary parameters and costs credibility. Two of three sentences earn their place.

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 2-param tool with no output schema, the description covers the key runtime expectation (preview + confirmation link, merchant-gated) that the schema cannot express. It omits any mention of what the preview payload looks like or whether repeated calls are safe, but nothing critical for correct invocation 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?

Schema description coverage is 100% and both params (code, action) carry detailed enum explanations, including the pt vs pt-BR nuance and per-action semantics. The description adds no parameter detail of its own, so the baseline 3 applies; the money/cents sentence is not tied to any parameter here.

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 ('Change the shop's languages') and immediately clarifies the real effect (returns a preview, not a live change), which separates it from the many settings_* siblings that mutate directly. An agent can identify the tool's scope without opening the schema.

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?

Clearly frames when this is the right call: it is a two-step flow where this tool produces a preview and confirmation link, and 'only the merchant, on that page, can make it happen.' It does not name a sibling alternative (e.g. translations_set for translation content, settings_store_defaults for other defaults), so it stops short of full routing guidance.

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