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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds valuable behavioral details: small drawings embed, larger ones are fetched via widget, status is posted back to conversation, and instructions on not re-fetching. It could be slightly more specific about size thresholds but is very informative.

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?

Two sentences plus a clear warning, all front-loaded. No wasted words; every sentence adds value. The structure first states purpose, then usage context, then behavioral caveats.

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?

Despite no output schema, the description comprehensively explains viewer behavior, embedding vs fetching, status reporting, and constraints. For a simple viewer with 2 parameters, it covers all necessary context for correct use.

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% and both parameters have descriptions. The description adds context beyond schema, e.g., source parameter explains public URL vs inline text and notes local files aren't available, and allow_file_open gets a clear default. This enhances understanding.

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 it opens an interactive DXF viewer and distinguishes it from siblings like describe_dxf (facts) and render_dxf (image). The verb 'open' combined with 'viewer' and the specific resource (DXF) make the purpose 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?

Explicitly tells when to use: 'when the user wants to see or explore the drawing themselves; for your own analysis use describe_dxf or render_dxf'. Also warns against re-fetching or blind-retrying, providing clear decision guidance.

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