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

No annotations are provided, so the description carries the full burden. It discloses that results are paged and include 'id/name/description and metadata-only marker', which is useful. However, it does not mention permissions, rate limits, error behavior, or clarify what 'metadata-only marker' means, leaving some ambiguity.

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, front-loaded with the tool's identity ('Universal catalog reader') and then efficiently details routing, optional filters, return shape, and usage. Every sentence earns its place; no filler or repetition.

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 5 parameters, no output schema, and no annotations, the description covers the essential behaviors: domain routing, facet/query filters, paging, and return structure. It stops short of explaining 'metadata-only marker' or edge-case behavior, but for a catalog listing tool, it is sufficiently complete for an agent to select and invoke it.

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 0%, so the description compensates by explaining domain (listing all enum values), facet (giving an example like 'button.hover'), and query ('free-text query'). It also references paging, which maps to page and page_size, though these are not explicitly named. The parameter meanings are largely clear from the description and names.

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 clearly states this is a 'Universal catalog reader' and specifies it routes by domain with a list of valid domains. It explicitly concludes with the use case: 'Use this for ANY merchant question about what options are available or show me X', which distinguishes it from siblings like diagnose or recommend.

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 provides a clear directive on when to use the tool: 'Use this for ANY merchant question about what options are available or show me X'. It does not explicitly name alternatives or state when not to use it, but the sibling tool names suggest distinct purposes, making the guidance more implicit than explicit.

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