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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower. The description adds genuinely useful behavioral context beyond them: it reports the exact achievable load and explicitly flags what the available plates cannot make. It stops short of describing rounding or per-side output structure.

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 tight sentences, zero filler, with the core action leading and the output behavior following. Nothing redundant with the schema or annotations.

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?

This is a self-contained calculation tool with no output schema, and the description adequately covers what the result contains (exact load plus any shortfall). Only minor gaps remain, such as whether output is per side and how rounding to the smallest plate is handled.

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 bar, unit, plates, target, collars and collarWeight in detail. The description only echoes the plates concept ('standard gym plates or the plates you list'), which maps to an existing default rather than adding new meaning. 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: work out which plates go on each side of a barbell to hit a target weight. The scope is clear and an agent can distinguish it from scoring tools like one_rep_max. It does not name the closest sibling (rpe_target_load), so it falls just short of the top score.

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 usage (plate math toward a target weight) but gives no explicit when-to-use or when-not-to-use guidance, and never references alternatives like rpe_target_load or warmup_sets. Usage must be inferred from the purpose statement.

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