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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses that the endpoint is credential-free and that localhost, private, link-local, and credentialed URLs are rejected. This is meaningful behavioral context, though it doesn't mention rate limits or return normalization details.

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 description is front-loaded with purpose followed by constraints and the sibling pointer. It's efficient, though the url guidance duplicates the schema's parameter description almost verbatim, which is slightly redundant.

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 a 100%-covered schema, an output schema, and readOnly/openWorld annotations, the description supplies the remaining needed context: the endpoint source, security restrictions, and an alternative tool. It's essentially complete for this simple single-item fetch.

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 coverage is 100%, so both 'url' and 'handle' are already documented in the schema, and the description largely restates the url validation rules. It adds little semantic meaning beyond what the schema provides, so the baseline of 3 applies.

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 states a specific verb (Returns), resource (normalized product detail), and mechanism (Shopify credential-free product handle .js endpoint). It clearly distinguishes itself from the listing sibling by naming shopify_products.

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 explicitly routes the agent to shopify_products 'to list Shopify products,' giving a clear alternative for the list use case. It doesn't spell out exhaustive when-not conditions (e.g., behavior for multi-shop or non-Shopify URLs), but the differentiation is solid.

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