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

With no annotations, the description must disclose behavior on its own. It explains the calculation model and scope, which is helpful, but it does not specify the output unit (e.g., Pa or bar), assumptions about fluid properties, or any limitations. The 'Powered by multicalci.com' provides no behavioral insight.

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 description is brief and front-loaded: the first sentence states the core calculation, the second expands scope. The only minor detractor is the promotional 'Powered by multicalci.com' clause, which is not essential but does not significantly hurt.

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?

The tool has 8 parameters and no output schema, so the description should provide more context about expected results and limitations. It describes the model but omits output units, applicable fluid types (e.g., single-phase incompressible), and any required validation. This leaves significant gaps for an AI agent selecting and invoking the tool.

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?

The input schema already describes each parameter with 100% coverage. The description adds value by linking parameters (fitting_k_total, elevation_change_m) to the physical model (K-method, elevation term), and by mentioning flow regimes (laminar/turbulent) that clarify the role of viscosity and density. This contextualizes parameters beyond their simple definitions.

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 clearly states 'Calculate friction pressure drop in a pipe' and specifies the method (Darcy-Weisbach with Colebrook-White). This distinguishes it from sibling tools like control valve sizing or pump power, making the purpose specific and unambiguous.

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 description enumerates handled cases (laminar/turbulent flow, fitting losses, elevation change), which implicitly defines when to use it. However, it does not explicitly state when not to use it or mention alternative tools for different calculations, so it lacks explicit exclusions.

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