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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, repeatable read operation. The description adds a list of example module types, which is useful context but not additional behavioral disclosure beyond what annotations provide. It does not mention pagination, rate limits, or return format, but the output schema exists to cover that.

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 a single concise sentence that is front-loaded with the action and resource, followed by parenthetical examples. Every word earns its place, and there is no redundancy or filler. It is appropriately sized for the tool's simplicity.

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 listing tool with no parameters and an output schema (declared but not shown), the description covers everything an agent needs: it explains what is listed, gives examples of the content, and implies the return is a list of modules. There are no missing prerequisites or edge cases. The output schema handles return structure, so this is complete.

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 tool has zero parameters, so the description does not need to compensate for missing parameter documentation. The baseline for a zero-parameter tool is 4, and the description adds no irrelevant parameter information. It correctly focuses on the tool's output rather than input.

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 verb 'List' and the resource 'all available hardware extraction modules supported by DatasheetVend', and gives concrete examples to further clarify scope. This is specific and unambiguous, and with no sibling tools to distinguish, it fully achieves its purpose.

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 implies usage: when you need an inventory of supported hardware modules. It does not explicitly say 'use when...' or provide exclusions, but there are no alternative tools to compare against, so the context is clear enough. A minor gap is the lack of explicit guidance on when not to use it, but this is not critical for a simple listing tool.

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