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

With annotations only declaring readOnlyHint=false / destructiveHint=false / idempotentHint=false, the description supplies the genuinely non-obvious behavior: the call is a no-op that returns a diff preview plus a confirmation link, and only the merchant can commit it. That two-phase, human-confirmed flow is exactly the kind of context annotations cannot encode.

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 compact sentences, with the effect (or lack of it) front-loaded after the one-line purpose. The 'Money is integer minor units' sentence earns no place because no money parameter is present, which is the only real waste.

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 4-parameter tool with full schema coverage, no output schema and only hint-level annotations, the description covers purpose, side-effect semantics and the confirmation mechanism — everything an agent needs to call it correctly and set expectations about the result.

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%, so field meanings are already carried by the schema and the baseline is 3. The description adds no parameter-level detail, and its sentence about money being integer minor units is irrelevant here since no monetary parameter exists in the schema, so it does not raise the score.

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 description names a specific verb and resource ('Set who the seller legally is') and the schema confirms it covers legal name, VAT number, phone and registered address — distinct from generic siblings like settings_details or settings_tax. An agent can tell what this tool configures 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?

It clearly frames the calling context — this call only produces a preview, and the actual change must be confirmed by the merchant on a linked page. It does not, however, contrast itself with adjacent settings tools (settings_details, settings_store_defaults), so routing guidance is good but not exhaustive.

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