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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. Beyond that, the description discloses nothing behavioral: it does not say what happens when inputs are missing, how 'auto' decides which quantity to solve for, what unit prefixes are accepted, or what is returned. Bare formulas are restated rather than behavioral context.

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?

It is a single short line with no filler, so there is no waste. But the terseness is under-specification rather than disciplined conciseness: the one sentence present is a formula crib sheet, not a front-loaded statement of purpose.

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 and annotations exist, so return-value and safety disclosure are not required. Still, for a four-parameter, all-optional calculator whose behavior hinges on the 'calculate' mode, the description leaves the core invocation question — which inputs to provide for which computation — unanswered.

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% (each of the four parameters is documented with units and examples), so the baseline is 3. The description adds no parameter meaning beyond the schema — notably it never explains the 'auto' default or which inputs pair with 'capacitance' vs 'charge' vs 'energy' modes.

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 gives only three capacitor formulas (C = Q/V, Q = C×V, E = ½CV²), which implies the domain (capacitance, charge, voltage, energy) but never states in words what the tool computes or which quantity it returns. The tool name and title carry most of the discriminating weight against siblings like calculator_inductor or calculator_ee_power; the description adds domain framing but no explicit verb+resource statement.

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 siblings such as calculator_energy, calculator_charge-related tools, or calculator_ee_power, and no explanation of when to supply charge/voltage/capacitance. The 'calculate' parameter's auto behavior is left entirely unexplained in prose.

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