list_domains

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

With no annotations provided, the description bears the full burden of behavioral disclosure. It reveals the return format (domain name -> circuit count) and the data source (Micro-Cap shipped reference circuits), implying a read-only listing operation. This is sufficient for a simple list tool, though it does not explicitly state the absence of side effects.

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 and front-loads the purpose, then gives the return format, and ends with practical advice. Every sentence contributes essential information without redundancy.

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?

Given that the tool has no parameters and an output schema exists, the description adequately covers purpose, usage, and return format. It is fully sufficient for an agent to understand what does this tool do and when to 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?

The tool has zero parameters, so there is no parameter schema to clarify. The description adds value by explaining what the returned data represents (domain name -> circuit count), which complements the empty input schema meaningfully.

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 clearly that the tool lists circuit-design domains for which Micro-Cap provides reference circuits. The verb 'list' and the resource 'domains' are specific, and the tool is differentiated from sibling tools that generate, simulate, or plot circuits.

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 instruction 'Start here before designing from scratch' provides clear guidance on when to use this tool, positioning it as a preliminary step before using generator or simulation tools. Although it does not mention sibling tools by name, it gives strong contextual cues for appropriate use.

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