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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The formula adds the core computation semantics, but it does not mention units, zero/empty inputs, or other behavioral constraints beyond the arithmetic itself.

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 a single formula with no wasted words and is front-loaded as the only content. Its brevity is appropriate for a trivial calculator, though it leans on the title to be interpretable.

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?

With an output schema and a fully described single parameter, the structured fields carry most of the load. Still, the description never explicitly says it computes total parallel resistance and omits usage context, leaving a small but real gap for an agent choosing among many calculator siblings.

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 100% and the sole parameter is documented as 'List of resistances in ohms,' so the baseline is 3. The description's Ri notation loosely maps to the array but adds no syntax, units, or edge-case meaning beyond the schema.

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 is only the formula R_total = 1 / Σ(1/Ri), which implies parallel equivalent resistance but never states in words what the tool computes. It relies on the title 'Parallel Resistance Calculator' to establish purpose, so the intent is inferable but not clearly expressed.

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?

There is no guidance on when to use this tool versus alternatives such as calculator_series_resistance or calculator_ee_resistor. The formula hints at parallel-combination semantics but provides no explicit usage context or exclusions.

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