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

The annotations already declare destructiveHint=true, idempotentHint=false, and readOnlyHint=false, establishing the mutation profile. The description adds a concrete side effect beyond annotations: "Changing the address resets its forwarding check." This is useful behavioral context, though it does not cover auth needs or the effect of changing productId.

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 two sentences with no waste. Purpose is front-loaded, and the behavioral caveat follows immediately, making it appropriately sized and easy to parse.

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 simple two-parameter mutation tool with rich annotations and no output schema, the description covers the core action and a key side effect. It is nearly complete, though it omits how the productId parameter behaves when null and does not route the agent among sibling tools.

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 the schema already documents both parameters, establishing a baseline of 3. The description adds slight meaning by implying that the address parameter triggers a forwarding-check reset, but provides no syntax or null-handling details beyond what the schema already states.

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 ("Set") and resources ("public support address" and "the product its emails belong to"), making the purpose clear. It does not explicitly differentiate this tool from siblings like update_mail_domain or send_support_inbox_test, so it 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?

The description gives no explicit when-to-use guidance, no prerequisites, and no alternative-tool routing. It implies configuration of the support address but leaves the agent to infer context and distinguish it from related sibling tools.

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