add_via

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

With no annotations, the description carries the full burden. It usefully discloses that diameter/drill default from the netclass and that the tool reports clearance problems with other nets on the outer layers. However, as an implicit write operation it says nothing about permissions, whether the placement is reversible, or what happens on netclass mismatch.

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 primary action and its key default behaviors are front-loaded in the first sentence, followed by a tidy Args block. It is slightly longer than strictly necessary but every line maps to a parameter or behavior, so nothing is wasted.

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?

An output schema exists, so return structure need not be spelled out. The description still adds the key return-side signal (clearance conflict reporting) plus defaults and constraints. Coverage of behavior is solid, with only the write/authorization semantics left implicit.

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 coverage is 0%, so the description must carry all semantics, and it does: it documents units (mm), the geometric role of x_mm/y_mm as the via centre, the netclass-derived defaults for diameter_mm and drill_mm, and the constraint that net_name must exist on the board. This fully compensates for the empty schema descriptions across all 5 parameters.

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 opens with a specific verb+resource: 'Add a through via at a position', and adds meaningful scope (sizing defaults from netclass, clearance reporting). The via resource is unambiguous against siblings like add_track/add_zone, though no sibling is named explicitly. Clear but not differentiated by name.

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?

There is no explicit when-to-use, when-not-to-use, or named alternative. The reader must infer usage purely from the action description; the only contextual precondition is that the assigned net 'must exist on the board', which is a parameter constraint rather than routing guidance.

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