open_file

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

Annotations already declare destructiveHint=true, and the description adds real value by disclosing exactly what is destroyed—the current design—which is the crucial operational fact. It stops short of warning about unsaved changes or prompting a save, so a small gap remains.

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?

A single sentence with the destructive side effect front-loaded in parentheses; 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?

Output schema exists, so return values need no explanation, and the single required parameter is fully documented in the schema. The only missing element is the unsaved-work implication of closing the current design.

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 the path parameter already enumerates supported formats, so the schema carries the burden. The description adds no format or path syntax detail beyond it, making baseline 3 appropriate.

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 specific verb (open) and resource (CAD file), plus the resulting state ('as the active design') and its side effect. It implicitly distinguishes itself from new_design by naming a file path rather than creating a blank design, though it never names the sibling.

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?

Usage is implied by the parenthetical that the current design closes, which hints at when this applies versus new_design. There is no explicit when-to-use guidance, prerequisites, or named alternative.

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