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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is covered. The description adds value beyond that: it discloses the granted-permission caveat ('grant_url ... when available') and the data-scope boundary ('No secrets or individual customer records'), which the annotations do not convey.

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: what it returns, the permission/grant caveat, the sequencing rule, and the data-safety boundary. Field enumeration is front-loaded and nothing is 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 no output schema, the description carries the burden of describing return values and does so by naming every field including the 'untagged' fallback semantics. It also covers the conditional grant_url case and reassures on data sensitivity, leaving no obvious gap for a read-only config getter.

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% for the single 'site' parameter, so the schema already carries the meaning including the fallback behavior. The description never mentions the site parameter, so it adds nothing on this dimension — baseline 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?

Opens with a specific verb+resource ('Read the Shopify customer-type configuration') and enumerates the exact fields returned, so the agent knows precisely what this returns. It does not explicitly distinguish itself from the similarly named sibling list_sales_tags, which is the only reason this falls short of a 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?

Gives a concrete workflow rule: read this before update_sales_config to preserve settings the user did not ask to change. That is real when-to-use guidance with a named alternative. It stops short of 5 because it never states when not to call it (e.g., if the user only wants the tag list, use list_sales_tags).

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