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

Annotations mark it as a non-read-only, non-destructive mutation; the description usefully adds that each swap is persisted as the line's choice, that it is individually reversible via choose_bom_part with null, and that unmatchable lines are reported and left untouched rather than erroring. That failure and reversibility behavior is exactly the context annotations cannot express, though auth/permission needs are unstated.

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?

Three sentences, front-loaded with the core action and matching criteria, followed by motivation and edge-case handling. Dense but every sentence carries information; parenthetical asides are compact rather than wasteful.

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 two-parameter mutation with no output schema, the description covers matching rules, the fee rationale, reversibility, and unmatchable-line behavior, which is most of what an agent needs before calling it. Missing only expected result shape (e.g., count of swaps) which the absent output schema would otherwise carry.

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 both parameters (design_id, boards) are already documented in the schema, including the boards default and design_id format. The description's value-add is matching logic (same value, package, at least equal voltage for capacitors) rather than parameter meaning, so the baseline 3 applies.

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?

Names a precise verb (move/consolidate), the exact resource (resistors, capacitors and inductors), and the target library (JLCPCB basic). It is unmistakably distinct from siblings like choose_bom_part or get_bom, which handle individual selection or retrieval rather than bulk library substitution.

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 rationale for when to use it (every off-library part adds a loading fee exceeding the part cost) and describes the scope limit (only R/C/L passives with readable value, SMD size and a basic equivalent). It also names the undo path (choose_bom_part with null). It stops short of an explicit 'do not use this if...' statement, so it's strong rather than exhaustive.

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