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

Annotations only mark it non-read-only, non-destructive and non-idempotent; the description goes much further by disclosing the two-step confirmation flow ("calling this changes nothing", returns a preview and a confirmation link, only the merchant can commit). This materially changes agent expectations and is exactly the kind of behavior structured hints cannot express.

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 tight sentences, front-loaded with what the tool does and immediately followed by the critical non-mutation caveat. No filler and no repetition of schema content.

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 12-parameter tool with a nested mapping object, no output schema and rich schema docs, the description covers the decisive behavior (preview + merchant confirmation) and money units. What remains unsaid is the post-confirmation outcome and any permission prerequisites, minor gaps given the schema richness.

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 92%, so the baseline is 3. The description adds one genuinely cross-cutting semantic not present in the schema: money values are integer minor units (cents), which matters because mapping targets price and compareAtPrice. That extra meaning justifies a 4.

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?

"Change a product import" gives a clear verb+resource that separates it from imports_create, imports_delete, imports_run and imports_inspect without needing the schema. It stops short of naming those siblings explicitly, so it lands at 4 rather than 5.

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?

The description tells the agent what happens on call (preview only, merchant confirms), which implies it is the tool for editing an existing import's settings, but it never states when to choose this over imports_create or imports_run. Usage is implied rather than stated.

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