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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context beyond them: results are 'capped' and the storefront URL is fixed (no URL argument needed), which tells the agent how results are bounded and what the tool assumes.

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?

Two tight sentences, no filler. The core operation is front-loaded and the routing hint to the sibling follows immediately. Every clause earns its place.

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 an output schema present, the description needn't explain return values, and it correctly avoids doing so. It also covers the discovery prerequisite and the fixed-URL assumption. Adequate for this low-complexity, two-param read tool, with only minor room to state the capping/pagination interaction.

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%: the type parameter's allowed values and the limit default/max are fully documented in the schema. The description only echoes 'selected by type' and 'capped', adding little beyond what the schema already provides, so the 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?

States a specific verb (List) and resource (capped URL records from a child sitemap) and the scope selector ('type'). It explicitly notes the storefront URL is fixed, which distinguishes it from a generic URL-fetch tool, and it is clearly separable from the sibling pristine_marketplace_sitemaps.

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?

Names the alternative/prerequisite tool explicitly: 'Use pristine_marketplace_sitemaps to discover child sitemap types.' That gives clear context for when this tool is the right follow-up, though it stops short of stating any exclusion condition (e.g. when not to use it).

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