print_html

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

No annotations are provided, so the description carries the full burden. It richly discloses behavior: 384px canvas, 1-bit black & white output, dithering support, data-qr feature, remote images/fonts supported. It doesn't state physical paper size (58mm implied), tearing behavior, or possible failure modes, but covers the major behavioral aspects thoroughly.

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 the core sentence, then layered technical details. It's a substantial paragraph but every sentence adds value—rendering constraints, dithering, QR, and guidelines are all non-redundant. Dense but justified given the complexity of a rendering tool.

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?

A complex tool (4 params, dithering, QR, rendering constraints) yet the description covers rendering canvas, output format, image handling, QR generation, mode/algorithm defaults, and guidance pointers. No output schema exists, but it accurately describes rendering behavior. Minor gaps: no physical print behavior details (paper, tearing) beyond feed_lines, and no error possibilities.

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 baseline is 3. The description adds substantial value beyond the schema: explains color/grayscale dithering quality, notes 'auto' keeps text razor-sharp, describes the data-qr replacement mechanism, and explains algorithm aesthetics (crisp vs smoother vs newspaper look). This adds depth beyond enum names.

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?

Specific verb+resource: 'Render ticket HTML and print it on the thermal printer.' Clearly distinguishes from siblings (preview_html just previews, print_markdown handles markdown). The purpose is unambiguous.

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?

Tells the agent to 'Preview with preview_html first,' explicitly names the alternate preview tool, and instructs calling design_guide for fonts/layout guidance or the thermal-print skill. Sibling differentiation is clear: preview before printing.

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