Preview a footprint

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safe-read behavior is covered. The description adds meaningful behavioral context: it lists exactly which primitives are visualized, notes the per-kind count and legend, and clarifies that this is ASCII preview output rather than a graphical render. It doesn't mention potential performance limits with very large footprints, but the added detail is solid.

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?

One well-structured sentence that front-loads the main purpose, enumerates the covered primitives with parentheses, and ends with a crisp scope qualifier. No filler or repetition of schema details.

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 read-only preview tool, the description covers the scope, output shape, and primitives well. The lack of an output schema means an agent won't know the exact character output structure, but the per-kind count and legend are described, which is reasonable. The main missing piece is guidance on error scenarios (e.g., non-existent component or file), but this is not critical for a lightweight preview tool.

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 100%, so all five parameters are already documented precisely, including defaults and units. The description adds value by explaining the overall rendering scope (which primitives appear and that there are markers/legend/counts), complementing the schema without duplicating it. This is above the baseline 3 because the description helps an agent understand what the output will include, which informs how to tune scale and max dimensions.

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 a specific verb (render), resource (footprint from a PcbLib file), and format (ASCII art visualisation). It enumerates the primitives covered and explicitly distinguishes itself from a full rendering ('A quick preview, not a rendering'), which helps differentiate it from sibling tools like render_symbol.

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's closing note ('A quick preview, not a rendering') implies when it should be used, and the sibling list makes render_symbol the clear alternative. However, it doesn't explicitly say 'use render_symbol for symbol previews' or state when a full rendering would be needed, so some guidance is left to inference.

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