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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful context beyond that: it requires a connected store, and notes that inventory units are EXACT and from the account, which clarifies the data source. No contradiction with annotations.

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 front-loaded with the core purpose and then gives a compact, useful list of the exact metrics returned. It is somewhat long, but every part adds relevant information for selecting and invoking the tool.

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 summary tool with one optional parameter, the description covers the tool's purpose, the data it returns, the prerequisite for use, and likely user queries. No output schema exists, but the description enumerates the output contents sufficiently.

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?

The only parameter, marketplace_id, is fully documented in the schema with a default and marketplace mapping, so schema coverage is 100%. The description adds no additional parameter-level meaning, which matches the baseline of 3.

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 purpose: produce a store-level summary of the seller's connected Amazon catalog, with an explicit list of metrics. This clearly differentiates it from product-level tools like my_products and asin_* tools, and from opportunity-specific tools like my_opportunities.

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 explicit use cases ('how is my store doing', 'summarise my catalog', or a dashboard overview) and notes the prerequisite of a connected store at Starter+ level. It does not explicitly mention when not to use this tool or name alternative tools, so it stops one step short of a 5.

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