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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: it specifies the depth of data returned ('including one level of nested (children) items') and the source ('from the live store'). This goes beyond the annotations and helps the agent understand what to expect.

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 plus a routing line, all of which carry meaningful information. The core purpose is front-loaded, the return fields are specified, and the use case is stated. No wasted words.

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 read-only list tool with one fully-documented parameter and no output schema, the description is quite complete. It covers what is returned, the nesting depth, and the use case. The only minor gap is that it doesn't describe pagination or limits, but for a navigation menu list this is likely a small dataset. The annotations cover the safety profile, so nothing critical is missing.

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 single parameter (companyId) is fully documented in the schema. The description doesn't add parameter-specific semantics beyond what the schema provides, but it doesn't need to. Baseline 3 is correct.

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 ('List'), a specific resource ('the connected Shopify store's navigation menus'), and enumerates the exact fields returned (handle, title, each item's label/URL, including one level of nested children). It clearly distinguishes itself from sibling tools like list_shopify_products or list_shopify_content by focusing on navigation menus and items.

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 explicitly states when to use the tool: 'Use to see the storefront's current menu structure before proposing a navigation change.' This gives clear context for use. It doesn't explicitly name alternatives or exclusions, but the routing line reinforces the scope. A 4 is appropriate because the use case is clear, though it doesn't explicitly say when not to use it or name alternative tools.

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