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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds substantial behavioral context: deterministic, no judgment calls, specific statistical methods (hypergeometric), scope (any format), and Commander-specific band signals. This goes well beyond the annotation baseline.

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, dense sentence that front-loads the main purpose and then systematically lists the analysis dimensions. Every phrase carries informative weight, and there is no filler or repetition.

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 an output schema exists and annotations are present, the description covers the tool's scope and capabilities thoroughly. It lists a comprehensive set of outputs and clarifies the deterministic/non-judgmental nature, making it complete for an analyst agent.

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 0%, so the description must compensate. It does so by explaining 'decklist' (cards), 'any format' (format), and 'Commander bands' (commander), adding meaning beyond the raw schema fields. However, it does not explicitly map each parameter to its exact usage constraints.

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 clearly states the tool performs deterministic statistical analysis of a decklist and enumerates specific outputs (mana curve, card types, probabilities, suggested land count, etc.). It distinguishes itself from siblings like rate_deck or upgrade_deck by emphasizing 'Pure data — no judgment calls.'

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 provides clear context for use: any format, statistical focus, and deterministic outputs. It implies when to use (when objective deck stats are needed) but does not explicitly name alternatives or exclusion criteria, so it falls just short of a 5.

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