brand_xmarket

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

Annotations already indicate readOnlyHint=true. The description adds value by specifying return fields (seller count, ASIN count, buybox days, control score) and per-marketplace behavior, confirming it is a safe query.

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 sentences, front-loaded with purpose and returns, followed by usage examples. No redundant information.

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?

Covers core purpose and return fields, but lacks details on threshold parameters (min/max) and explanation of control score. No output schema, so description could provide more completeness.

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 only 20% (only 'brand' described). The description does not explain the other 9 parameters (marketplace_id_in, min/max counts, etc.), leaving the agent without guidance on filtering options.

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 the tool checks brand presence on Amazon US, UK, and Walmart, and lists specific return metrics. It distinguishes from siblings by focusing on multi-marketplace brand presence, with explicit user query examples.

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 explicit example user queries ('does this brand sell on Walmart', 'cross-marketplace presence for Nike'), making it clear when to use. No when-not-to-use guidance, but the context is sufficient.

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