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

Annotations already declare safe read operations. Description adds useful context: returns ~60 months, currency is reporting, aggregates many auction houses, and notes output is keyless. No contradictions.

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?

Three sentences, each essential: first explains output, second details currency and source, third gives usage instruction. No unnecessary words.

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 simple tool with one parameter and no output schema, description covers return values, data scope, and usage. 'Keyless' might be slightly unclear but overall complete.

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% with clear description for the single parameter 'slug'. Description reinforces the parameter's source and format, adding value beyond 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?

Description clearly states it returns monthly auction price/volume history per distillery, specifying exact metrics (max/min/mean bid, volume, lots), currency, and source. The name 'distillery_prices' is unambiguous. Distinguishes from sibling list_distilleries which provides slugs.

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?

Explicitly instructs to pass a distillery slug from list_distilleries, with examples. Does not explicitly state when not to use or provide alternatives, but the context is clear for a simple lookup tool.

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