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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds the output unit (kW) and the governing equation, but says nothing about edge cases such as zero head/flow or efficiency bounds beyond what the schema states.

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, formula front-loaded after the purpose statement, no restated boilerplate. The trailing 'See list_bundles' sentence is marginally useful but slightly dilutes the focus.

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 values need not be spelled out, and the core inputs and unit system are given. However, the density mention creates a real ambiguity about what the tool actually accepts, leaving the definition not fully self-consistent for such a simple three-parameter 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 description lists 'fluid density' as an input, but the schema contains only head_m, flow_m3h and efficiency (100% coverage) — there is no density parameter. This phantom parameter is actively misleading and undercuts the otherwise adequate schema documentation.

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 ('Compute pump power requirement') and backs it with the exact formula P=ρ·g·H·Q/η, which pins down the calculation unambiguously against siblings like calculate_hydraulic_pressure or calculate_pipe_flow_rate.

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?

'Use for fluid system design' implies a domain but names no alternative tool or exclusion, and the only pointer is to list_bundles, a meta-tool rather than a competing calculator. Usage is inferred rather than specified.

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