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

Annotations already declare readOnly, idempotent, non-destructive, openWorld, so the safety profile is covered. The description adds real context beyond them: deterministic, no model call, and the accepted input format. It omits failure behavior (e.g. what happens on a binary file) and any size/rate limits, keeping it short of a 5.

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 sentences, front-loaded with the action and extraction scope, then the non-goal and the determinism note. Dense but every clause carries information; the parenthetical asides add a little clutter.

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 an output schema present, return values need not be explained, and the description still names the payload components. It covers input format, scope, non-goal, and determinism — enough for correct invocation; only error/edge-case handling is left implicit.

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 baseline is 3. The description's format constraint ('a text file — NOT a binary .PcbLib/.SchLib') reiterates what the documentPath schema already states, and partName is not mentioned at all in the description text.

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 ('Parse an Altium Designer ASCII footprint export') and enumerates exactly what is extracted (footprint name, pad geometry, layer map, review verdict). It explicitly excludes binary .PcbLib/.SchLib and the build-from-PDF sibling, so an agent can separate it from datasheetvend_extract_kicad_* and the Altium build path.

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?

Gives a clear condition ('This reads an EXISTING Altium file; it does not build one from a datasheet PDF') and names the alternative for the build case ('Altium Assist output pack on a completed extraction job'), though that alternative is not a literal sibling tool name. The when-not is explicit; the when-to-use is implied by 'existing Altium ASCII export'.

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