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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description only needs to add context, and it does: it discloses the UI-window side effect, the three-year run horizon as a hard limit, and that the circuit is persisted as the person's project and reopens in the lab as built. It stops short of saying what happens if a window is already open or what the call returns to identify the new circuit.

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?

Purpose and routing information are front-loaded before the Args block, and each sentence carries real information about behavior or sequencing. It is somewhat long and leans on descriptive imagery ('as the lab's canvas shows it', 'every card lights up in turn') that costs tokens without changing agent behavior.

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 zero-required-parameter tool with no output schema, it covers purpose, prerequisites, follow-on tools (circuit_step, run_circuit), the three-year scope limit, and persistence semantics. What is missing is the handoff detail — how the agent identifies or references the circuit it just created when calling circuit_step, given no return value is documented.

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 0%, so the description must carry both optional parameters, and it largely does: name is given a usage pattern and a concrete example ('RSI dip on KO, tested forward'), and fresh is given an explicit false/else branch meaning. The only gap is that null is the schema default but the description never states what null does relative to fresh=true.

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 opens with a specific verb and resource — opens a window where a circuit of QuanterLab lab cards is assembled step by step — and describes the visible progression (cards arrive, wires join, cards light up on run). It explicitly distinguishes itself from start_test (ready-made tests), circuit_step (adding cards), and run_circuit (execution), so the agent can place it among siblings without opening another schema.

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?

It names the conditions for use — a person's own idea that no ready test covers, or a change to a previously built circuit via fresh=false — and names the alternatives explicitly (start_test, circuit_step, run_circuit). The 'a longer test runs in the lab' clause also tells the agent when this tool is NOT the right vehicle.

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