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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so safety is covered. The description adds real value beyond that by disclosing the comparison output surface (note pyramids, shared/distinct accords, performance scores, concentration, price delta), which matters since there is no output schema.

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?

A single front-loaded sentence that names the operation first and then the comparison dimensions. No filler, no repetition of the title, every clause earns its place.

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?

With no output schema, the description usefully enumerates what the comparison returns and the parameters are fully documented, so an agent can call it correctly. Minor gaps: behavior on unresolvable or identical inputs is unspecified.

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%: both parameters are documented as 'slug or name'. The description adds nothing about how inputs are resolved (e.g., ambiguous names, invalid slugs), so 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 ('side-by-side comparison' of two fragrances) and enumerates the compared facets, so the agent knows exactly what it produces. It does not explicitly distinguish itself from close siblings like find_similar or find_dupes, leaving that differentiation to inference.

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 never states when to choose this tool over find_similar, find_dupes, or get_fragrance. A user asking 'how do these two stack up' is implied, but no alternatives or conditions are named, so the agent gets no routing guidance.

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