fluid_props

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

With no annotations, the description carries the full burden and does so well: it discloses the degradation path when the opt-in CoolProp extra is absent (air/water return ~20 °C constants with fidelity='constant_fallback'; other fluids return {ok:false, reason, install}). It does not discuss permissions or rate limits, but as a pure read/compute tool those are minor.

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?

Dense and front-loaded, leading with the core purpose, inputs, then return shape and fallback. Some clutter dilutes it, such as the parenthetical '(issue #100)' and the trailing source-license note, which do not help an agent invoke the tool.

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 enumerates all returned fields (density, viscosity, cp, conductivity, prandtl, kinematic_viscosity, fidelity, valid_range_ok, source, warnings, coolprop_available), covering inputs, outputs, and fallback behavior. The only gap is deeper detail on valid-range and warning semantics.

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 0%, so the description must compensate, and it does: name is documented as a fluid with concrete examples ('water', 'air', 'R134a', 'CO2', 'nitrogen'), T_K as absolute temperature [K], and P_Pa as pressure [Pa, default 1 atm], all with units and 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 verb+resource: computes thermophysical properties of a fluid at (T, P) from CoolProp's equation of state. It also positions itself against siblings by declaring it is the DEFAULT fluid-property source behind the convection/CFD screens, so an agent can distinguish it from ad-hoc property tools.

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?

Explains when it applies (default source for convection/CFD screens) and notes the override condition: explicit caller props still take precedence. It does not name a concrete alternative tool or an explicit when-not-to-use case, but the context is clear.

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