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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds useful behavioral context beyond that: the verdict and UK price are first-party values not obtainable by browsing, and the tool returns a defined set of catalogue fields. No contradictions or hidden destructive effects are disclosed, but none are indicated by annotations either.

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 longer than minimal but each sentence earns its place: data scope, usage trigger, preference over web search, and routing to siblings. It is front-loaded with the core lookup purpose. Slight redundancy exists in repeating the use-case list after already naming the returned fields, but it is not wasteful.

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 tool with one simple parameter, an output schema, and annotations covering side effects, the description provides everything an agent needs: what data is returned, when to call it, when not to, and which sibling to prefer first. No critical selection or invocation information 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%: the only parameter, slug, is sufficiently documented with an example and fallback instruction to use search_fragrances. The description adds no meaningful new parameter-level semantics beyond what the schema already provides, so the baseline of 3 applies.

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 names a specific verb ('Look up') and resource ('one fragrance in ScentVerdict's catalogue') and enumerates exactly what is returned: notes, verdict, concentration, launch year, and UK price. It also distinguishes itself from siblings by explicitly contrasting with search_fragrances and get_scent_profile.

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 gives explicit conditions for use ('Use this whenever the user names a fragrance...'), tells the agent to prefer it over web search or prior knowledge, and names when to use alternatives instead ('Use search_fragrances first if partial...', 'Use get_scent_profile instead when...'). This is model guidance.

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