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

Annotations already establish readOnly, idempotent, open-world, and non-destructive behavior. The description adds useful behavioral context by stating it returns each herb's assessment status and whether an EU monograph or list entry exists, reinforcing the open-world nature with 'has assessed or is assessing.'

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, front-loaded with the subject, then search dimensions, return semantics, and representative queries. No filler or redundant restatement of the tool name.

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 6-parameter search tool with no output schema, the description covers what the tool does, what it returns, and how an agent might phrase queries. It could be slightly stronger on interpreting status codes, but the schema already documents those.

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 restates search fields already covered by the schema and adds example queries, but it does not deepen parameter-level understanding beyond what the schema provides.

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 and resource: 'Search the European Medicines Agency (EMA) herbal medicines inventory,' and further scopes it to HMPC-assessed plant substances. The example questions make it easy for an agent to distinguish this from generic herb or monograph tools.

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?

Clear context is provided: search by common/Latin/botanical name, therapeutic area, or status, with example questions showing intended use. It does not explicitly name sibling alternatives or give when-not-to-use guidance, so it stops 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.