Change a part setting

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

With no annotations, the description carries the whole burden. It usefully discloses that the target part must already exist in the circuit and that the change is meant to sit between simulation runs, but says nothing about permissions/prerequisites (open circuit, valid ref), whether a re-run is needed to observe the effect, or what happens for an unknown prop key.

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 short sentences, front-loaded with the mutation and followed by the usage timing; the inline examples replace what would otherwise be a longer explanation. No filler or repetition.

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 mutating tool with a free-form nested props object and no output schema, the definition leaves the biggest question open: which prop keys each part type accepts and where to get a valid 'ref' (presumably tinkercad_list_parts). It is adequate to attempt a call but not to call correctly on the first try.

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 only 50%: the 'props' object is documented in both places, and the description adds genuine meaning by giving concrete key/value examples (position 0-1, distance_cm). The 'ref' parameter has no description anywhere, and the fact that valid prop keys vary per part type is left unexplained.

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?

Uses a specific verb ('Changes a setting') against a specific resource ('a part that is already in the circuit'), and the two examples (potentiometer position 0-1, ultrasonic distance) make the operation concrete. The 'already in the circuit' qualifier implicitly separates it from tinkercad_build_circuit, though no sibling is named explicitly.

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?

'Use it between simulation runs to test different inputs' gives a real when-to-use condition tied to the simulate workflow. It stops short of stating when NOT to use it (e.g. use build_circuit to add a new part, or that the circuit must already be open) or naming alternatives explicitly.

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