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

Annotations already declare readOnly/openWorld=false/destructive=false, so the safety profile is covered. The description goes further by disclosing the return format, the near_misses behavior when no name matches every word, and the side-purpose of design_id, which is meaningful content beyond the annotations.

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?

Four sentences, all earning their place, front-loaded with the core action and return value before the fallback and design_id details. Slightly dense but no filler.

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 does the job of explaining the return shape and the near_misses fallback, plus how design_id affects recording. Complete enough to call correctly, though the exact result structure (list form, exact matches field) 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 coverage is 100%, so baseline is 3, but the description adds real value: example query strings ('LGA-14', 'QFN-24', 'SOIC-8') and the purpose of design_id (lookup recorded for the design's dossier; a registered part belongs to it) beyond the schema's terse note.

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: 'Search KiCad's standard footprint libraries', and specifies the return type ('Library:Footprint' strings for the footprint= argument). The resource ('footprint libraries') naturally separates it from search_kicad_symbol, but it never explicitly contrasts with that sibling, so it stops short of a 5.

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 concrete query-construction guidance ('package family and pin count', optionally body size or pitch) and explains the near_misses fallback condition. It lacks an explicit when-not clause or a direct pointer to search_kicad_symbol for symbol lookups.

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