engineering.thermal_expansion_strain

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

Annotations already declare read-only and idempotent behavior, and the description adds substantive context beyond that: sign convention for contraction, unit consistency for ΔL, optional return behavior, no rounding, and the 1D free-expansion limitation.

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 formula and optional length-change behavior are front-loaded, and each subsequent sentence adds a distinct constraint (units, sign, input pitfall, scope, rounding). There is 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?

An output schema exists, so return structure does not need explanation, and the description still covers all invocation-critical details: input semantics, optional output, units, rounding, and scope limits. Nothing important for correct use is missing.

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 fully, and it does: alpha is identified as the linear expansion coefficient in 1/K, delta_t as temperature change in K or °C with negative meaning contraction, and length as a positive optional input whose unit matches ΔL.

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?

The description names the exact quantity and formula (ε = α·ΔT) plus the optional length-change output, so the tool's purpose is unambiguous. It also scopes the tool to 1D free thermal expansion and excludes constrained thermal stress, though it does not explicitly contrast with engineering.mech_strain.

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?

It gives a key usage rule — delta_t must be a temperature change, not an absolute temperature — and explains when the optional length output applies (length > 0). It also clearly excludes constrained thermal stress, but does not name a specific alternative tool for that case.

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