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

Annotations already signal read-only, idempotent, non-destructive behavior. The description adds meaningful behavioral context beyond those annotations: constraints are 'filtered rather than approximated,' season/occasion/intensity scores come from ScentVerdict, budget is checked against current UK bottle prices, and each row includes price, bottle size, and price per millilitre. No contradiction with annotations exists.

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 dense but every sentence earns its place: use case, constraint semantics, output contents, optionality, and sibling routing. It is front-loaded with purpose and provides the most decision-relevant information early.

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 an 8-parameter optional tool with an output schema and annotations, the description covers selection behavior, output fields, optionality, and the correct alternative tool. Nothing an agent needs to decide whether and how to call it correctly is missing.

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 baseline is 3. The description goes further by clarifying that all constraints are optional and the budget is applied against real current UK prices, not approximated. This adds useful nuance beyond the schema's bare 'Maximum price in GBP' definition, though not every parameter is individually elaborated.

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 opens with a specific verb and resource: 'Recommend fragrances matching what the user describes.' It then enumerates the constraint dimensions and explicitly distinguishes this tool from find_similar_fragrances by noting it applies when the user names no fragrance to anchor on.

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?

It gives an explicit trigger condition: 'Use this when the user wants a suggestion but names no fragrance to work from' and provides concrete examples. It also names the alternative: 'Use find_similar_fragrances instead when they name a fragrance to anchor on,' so the agent knows exactly when to choose the sibling.

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