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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world behavior. The description adds useful behavioral context by stating the return values: battery count, wiring configuration notation (e.g. 2S3P), and step-by-step wiring instructions. It does not cover edge cases such as rounding when the target is not exactly achievable, but the output disclosure is substantive.

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?

Two sentences, front-loaded with purpose and followed by return values. No redundant or filler content; every sentence contributes to understanding what the tool computes.

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?

For a read-only calculator with four required, fully described parameters and no output schema, the description is nearly complete: it explains purpose and expected outputs. It stops short of clarifying the relationship with calculate_battery_bank or stating assumptions about rounding and infeasible targets.

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%, and all four parameters are clearly documented with types and examples. The description adds no parameter-level semantics beyond restating target voltage and capacity, so the schema carries the full burden and the 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?

States a specific verb and resource: determines series/parallel battery arrangement for a target voltage and capacity, and explicitly names what is returned. However, it does not distinguish itself from the sibling tool calculate_battery_bank, which sounds highly overlapping and could confuse an agent choosing between them.

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 explains what the tool does but gives no when-to-use guidance, no exclusions, and no reference to alternatives. Given the presence of a similarly named calculate_battery_bank sibling, this omission is a real gap.

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