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

Annotations only supply the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true). The description adds context the annotations cannot: the successful path overwrites circuit.py, the rejected path is preserved as attempt_N_circuit.py and leaves the design untouched, sourcing makes network calls, and the run can take minutes. That is exactly the state-change, failure-mode and latency disclosure the annotations omit.

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?

The purpose and the check list are front-loaded, and every clause carries information (checks performed, return shape, file outcomes, runtime). The long enumerative sentence is dense but justified; only minor tightening is possible.

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?

With no output schema, the description carries the return burden and does so adequately: 'Returns accepted plus blocking findings to fix and warnings.' For a mutating, open-world compile step the failure/persistence semantics and latency are also covered. Only the precise findings structure is left unspecified.

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 100%, so the schema already documents design_id, code and check_sourcing, including formats and defaults. The description mentions supplier sourcing among the checks, loosely implying check_sourcing, but adds no syntax or semantics beyond the schema. Baseline 3 applies.

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-and-resource pair ('Compile and check a complete SKiDL script') and then enumerates exactly what is checked: symbol/footprint pre-flight, SKiDL, ERC score, KiCad ERC, floating subsystems, missing footprints, supplier sourcing. This clearly separates it from siblings like edit_circuit (incremental edits) or check_net_rules (board-level rules).

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: this is the full-script submission/validation gate, and the 'takes up to a couple of minutes' note hints it is the heavyweight option versus edit_circuit. However, no sibling is named and there is no explicit when-not guidance (e.g. use edit_circuit for small tweaks), so the agent must infer routing.

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