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

With no annotations, the description carries the full burden and does meaningful work: it discloses that the DEW point is used as the saturation basis (critical for blended refrigerants) and that the result is in Fahrenheit. It omits error behavior (invalid refrigerant, out-of-range inputs) and whether the refrigerant argument accepts trade names or only numeric designations.

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?

Four short sentences, each carrying distinct information (output, inputs, audience, method, benchmark). The core purpose is front-loaded 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?

For a small compute tool with no output schema and no annotations, the description covers the return value (Fahrenheit superheat), the computation basis, and a sanity-check range. It lacks only supported-refrigerant coverage and failure behavior, which keeps it short of complete.

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 for three undocumented parameters. It does clarify units for suction_psig (psig) and suction_line_f (F) and the saturation basis, but the refrigerant parameter's accepted values are never described, leaving a real 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 computed quantity (superheat in Fahrenheit) and its exact inputs (suction pressure psig, suction-line temperature F). It is readily distinguishable from the sibling subcooling and pt_lookup tools, which compute different quantities.

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?

Provides clear audience and applicability guidance ('for certified HVAC technicians (EPA 608; A2L where required)') and an interpretive benchmark ('typical TXV target: 8-12F'). It does not explicitly name alternatives such as subcooling or pt_lookup or state when to prefer this over them, so it stops short of a 5.

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