Switch a placed part to another variant of its device set, updating value, JLC code, and attributes to match the chosen variant for variant-based passive libraries.
Switch a part to another device variant of its device set (how variant-based passive libraries change value; the variant's JLC code and attributes follow). Example variant: '_680R_1%_1/10W'.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | Yes | ||
| device_variant | Yes |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, covering the mutation profile. The description adds useful consequence detail — 'the variant's JLC code and attributes follow' — telling the agent the swap changes more than just the value. It does not contradict annotations, but says nothing about reversibility, permissions, or failure behavior.
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 front-loaded sentence plus a compact example. No wasted words; the core action is stated first and the clarifying example follows.
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 2-param mutation tool with no output schema, the definition covers purpose and side effects but omits what happens to referenced parts that don't exist, whether the change is reversible, and any preconditions. Annotations carry the safety profile, so the gaps are moderate rather than severe.
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 description coverage is 0%, so the description must carry parameter meaning. It supplies a concrete example of the device_variant format ('_680R_1%_1/10W'), which genuinely helps, but leaves 'ref' completely unexplained and gives no format guidance for it.
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+resource ('Switch a part to another device variant of its device set') and clarifies the domain concept in a parenthetical. It implicitly contrasts with set_part_value (value vs. variant) but never names the sibling, so differentiation is inferred rather than explicit.
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?
No when-to-use guidance, no alternatives, no prerequisites. The agent must infer that this is the right call when it wants a variant swap rather than a value change (set_part_value). No exclusions or conditions are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.