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

No annotations are provided, so the description carries the full behavioral burden. It discloses that the calculation uses the same engine as rofilter.cn, lists the returned performance values, and gives practical interpretation thresholds for flux. It does not describe error behavior or side effects, but for a calculation tool this is otherwise fairly transparent.

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 compact and front-loaded: it states the calculation first, then explains that this is the core tool, then gives interpretation guidance. Every sentence adds useful information, and the flux thresholds are especially valuable for an agent evaluating results.

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?

Given the nested input schema and absence of an output schema, the description does a good job listing the key return values and interpreting flux. The schema covers detailed parameter semantics. It does not specify the exact response structure or explicitly route agents to list_elements for element names, leaving a minor completeness gap.

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 100%, so the schema already documents the water, design, and stage parameters in detail. The description restates the major inputs and adds a vessel-sizing heuristic, but does not add units, formats, or constraints beyond what the schema provides. Baseline 3 is appropriate.

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 states a specific action and resource: running a complete reverse-osmosis system design calculation, and it enumerates the main outputs such as feed pressure, permeate TDS, concentrate concentration, energy, flux, and stage-by-stage results. It also calls itself the service's core tool. It does not explicitly distinguish itself from siblings like analyze_water or list_elements, so it falls short of a 5.

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 implies when to use it: when feed water quality, recovery, permeate flow, and membrane arrangement are known and a full design calculation is needed. It adds useful interpretation guidance for average flux and vessel sizing. However, it does not explicitly name alternatives such as analyze_water or state when not to use this tool, so guidance remains implied rather than explicit.

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