list_metafields

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

No annotations provided, so the description carries the full burden. It correctly identifies this as a read operation, describes the output fields, and normalizes empty results. It does not mention pagination beyond the 'first' parameter which is already in schema, but overall behavior is well-conveyed.

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 sentences: first states purpose, second explains return content, third gives usage guidance. Front-loaded with key information, no fluff, every sentence adds value.

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 list tool with 3 parameters and no output schema, the description covers purpose, return structure, usage context, and a common scenario (empty results). It could mention pagination behavior (cursor-based) but overall is fairly complete.

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?

The description adds context for the 'namespace' parameter (scope to one app/integration, recommended for many metafields). However, it does not mention the 'first' parameter (pagination) though schema has 67% coverage. The description provides some added value beyond schema but not fully compensates for the missing parameter description.

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 clearly states the tool lists metafields for a single Shopify resource, specifies what is returned (namespace.key, type, value, description), and distinguishes from siblings like set_metafield and delete_metafield. It is specific with verb and resource.

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 provides clear usage context: use before set_metafield or for auditing, and recommends passing namespace when resource has many metafields. However, it does not explicitly state when not to use it or name alternative tools beyond set_metafield.

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