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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds real context beyond them: deterministic execution, the null-for-unknown / empty-string-for-missing-evidence convention, and that unknown evidence stays unknown rather than being inferred. The scope exclusion (no fuse selection or certification) further sets expectations.

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 sentences are front-loaded and dense, with the determinism claim first and the calling conventions following. Every clause carries information, though the null/empty-string rules could be tightened.

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?

An output schema exists, so return values need no explanation. For a tool with two large nested input shapes, the description covers the calling convention well but says nothing about units handling or what the calculators actually derive, leaving some gap for a tool of this complexity.

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 must carry the meaning, and it does explain the critical null/empty-string convention and which shape each kind requires. It does not, however, clarify the semantics of the many individual fields (units, evidence fields, model limits), so it only partially compensates for the coverage 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 ('Run the existing wire or DC-DC calculator deterministically') and distinguishes the two operating modes by kind. It does not explicitly differentiate itself from siblings like analyze_system, but the calculator purpose is clear.

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 clause 'No fuse selection or installation certification' sets a boundary on what this tool will not do, and the kind=wire / kind=dc-dc mapping implies which mode to pick. However, there is no guidance on when to prefer this over analyze_system or the other siblings, so the when-to-use is only implied.

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