is_root_schematic

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new behavioral semantics — the rule that rootness is determined by whether any sheet of the project references the file, and that root_path resolves to the project's top-level sheet — which an agent cannot get from structured fields. Return shape details are legitimately omitted because an output schema exists.

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 is front-loaded in the first sentence, followed by the definitional rule and then the argument note, which is the right order. The middle paragraph is slightly long for a one-parameter read tool, but every clause contributes real meaning.

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?

The tool is simple (one optional string parameter) and an output schema exists, so return values need no explanation. The description supplies the domain rule needed to interpret the result; only the resolution of relative paths and the meaning of 'configured default' are left open.

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 carries the full burden and largely succeeds: it identifies schematic_path as a path to a .kicad_sch file and states it is optional, with omission falling back to the configured default. The reference to a 'configured default' is not explained (where it is configured, what it points to), leaving a small gap.

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 ('Check if a schematic is the root or a sub-sheet') and then defines what root/sub-sheet mean, which makes the domain concept unambiguous. It doesn't name the closest siblings (list_hierarchy, get_sheet_info, validate_hierarchy) that an agent might confuse it with, so it stops short of full sibling differentiation.

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?

The description implies usage by defining the root/sub-sheet concepts, and it gives one concrete operational rule (omit schematic_path to use the configured default). It never says when to prefer this over list_hierarchy or get_sheet_info, nor what happens on a path that isn't in a project, so guidance is 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.