get_layer_stack

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description usefully adds the dual data-source behavior (live design rules vs. a supplied file), but says nothing about failure modes when no design is open or the file is malformed. Adequate given the annotation coverage.

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 tight sentences, front-loaded with the returned contents before the source/parameter detail. No filler or redundancy. Slightly terse but every clause earns its place.

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 read-only tool whose annotations already cover the safety profile, the description covers what it returns, where it reads from, and the parameter's accepted file types. No output schema exists, but the description enumerates the returned fields, so an agent has enough to call it correctly.

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% and the single stackup_file parameter carries no schema description, so the description must compensate. It does: it names the parameter and specifies acceptable formats (.estackup or .edru), which the schema does not provide. That is genuine added meaning, though it omits what happens if the file conflicts with the open design.

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 resource and the exact data returned (copper and dielectric thicknesses, Er, materials), so an agent knows what comes back. The verb 'get' is implicit but the resource is unmistakable. It does not explicitly contrast with the related get_design_rules/get_board_summary siblings, which keeps it out of 5 territory.

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 tells the agent where the data is sourced from (the open design's Fusion design rules, or an external stackup_file), which is an implicit usage cue. But it never states when to prefer this over get_design_rules or list_design_rules, nor any prerequisite like a design being open, so guidance stays implied rather than explicit.

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