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

Annotations only cover the safety profile (readOnlyHint=false, destructiveHint=false), and the description adds substantial behavioral detail: exactly what is preserved (reference, value, position, rotation, side, lock, schematic link), how nets transfer pad by pad, that schematic Footprint fields are updated, and what is reported. This goes well 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?

A single dense paragraph front-loaded with the core action and its scope. Every clause carries operative detail, though the run-on structure makes it slightly harder to scan than a segmented form would.

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 ('Reports new pads left without a net and old nets left behind'). Combined with the schema-resident wait_s/get_board_job guidance, the agent has enough to invoke and interpret the call, though alternative selection remains unaddressed.

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 67% and the description supplies the key missing semantics: pad_map direction (NEW pad number to OLD pad whose net it takes) and the footprint 'library:name' format. rot_deg and refs are only obliquely covered, leaving some gap but adding real value over the schema.

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 ('Replace footprints in place with another footprint from a library') and pins down the exact scope (project's fp-lib-table, library:name format). It is clearly distinguishable from siblings like place_footprints or search_kicad_footprint without opening any schema.

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 use case (in-place footprint replacement) is strongly implied and the pad_map caveat for 'packages numbered differently' is context, but the description never states when to choose this over place_footprints or other placement siblings, nor any prerequisites beyond the fp-lib-table reference.

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