list_vias

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

With no annotations, the description carries full burden. It discloses that the tool is read-only, returns a list of via objects with specific fields (position, diameter, drill, net, layers), and provides an example. It does not mention side effects or authorization, but for a listing tool this is sufficient.

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 extremely concise: two sentences plus a single example. Every sentence is informative, no fluff. The example front-loads the return format, making it immediately useful.

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 no parameters and the presence of an output schema (though not provided as a formal schema, the description outlines the return), the description is complete for a simple list tool. It covers what is returned and the data fields. Minor missing details like ordering or empty state are acceptable for this complexity.

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 no parameters, so the input schema adds no meaning. The description compensates by detailing the return structure and providing an example, adding value beyond the schema. Baseline for 0 parameters is 4, and the description meets that.

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 'List all vias on the board,' specifying the verb 'list' and resource 'vias'. It distinguishes from sibling tools like create_via, list_tracks, and list_footprints by focusing exclusively on vias and providing a clear return format.

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 a list of vias is needed, but does not explicitly state when not to use it or mention any alternatives among siblings. It lacks guidance on preconditions or related tools, which is acceptable for simple queries but leaves room for improvement.

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