em_field

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

No annotations are provided, so the description carries the full burden. It gives explicit kind-specific formulas and the return shape/units ({b_t, b_mt, …}), but does not explicitly state statelessness, side-effect-free behavior, or default/null handling.

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?

Front-loads the purpose and the two source formulas in a few compact lines. Every clause adds technical detail, with 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?

No output schema exists, but the description names return fields and units. It covers the physics and parameter roles, yet leaves default/null semantics implicit, a minor gap for a 5-parameter schema.

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 compensate. It maps kind to wire/solenoid formulas and ties distance_mm, turns_per_m, current_a, and mu_r to variables in those equations, though it does not clarify required vs optional parameters or defaults.

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 computation — exact magnetostatic field — and names the two canonical sources with their formulas. The 'NO solver' phrase distinguishes it from numerical siblings such as em_fullwave_submit.

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?

Clearly limits use to two canonical sources and contrasts with a solver, so the context of use is explicit. It does not name an alternative sibling for arbitrary geometries or numerical field solving.

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