render_board

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

Annotations already establish readOnly/idempotent/non-destructive, so the bar is lower. The description adds genuinely useful operational context: it is a fresh export, an optional matplotlib dependency is required, and it returns the PNG plus its save location. It does not contradict the 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?

Front-loaded with what the image contains, then parameter hints, then the dependency and return note. The rendered-element list is long but every item is meaningful; little waste.

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 an image-producing tool with no output schema, the description tells the agent it gets a PNG and where it lands, plus the dependency requirement. Sufficient to invoke correctly, though it could say more about what 'traces' toggling does.

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 the load. It clarifies highlight_nets (regex of nets, colored and labeled at pads), region_mm ([x0,y0,x1,y1] zoom box), and plan (a route_pair plan drawn on top), but leaves 'traces' and 'out_path' only obliquely covered by 'where it was saved'.

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?

States a concrete verb+resource: producing a PNG picture of the board's current state, and enumerates exactly what is rendered (outline, pads, holes, keepouts, part names, traces with colors, vias, pours). No sibling tool renders an image, so it is trivially distinguishable.

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 explains what each option does and connects 'plan' to a dry_run output, but never states when to reach for this tool versus e.g. get_board_summary or routing_status, nor any exclusions. Usage is implied by the content, not guided.

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