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

Annotations already indicate read-only, and the description adds behavioral context: data source (Europe PMC publication counts), time windows (90-day vs two-year baseline), output components (trend, z_score, etc.), and update frequency ('Updates: daily'). It does not discuss failure modes or rate limits, but given the read-only hint, the added detail is sufficient.

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 two sentences with no filler. The first sentence packs the result definition, data source, output fields, and comparator into one dense but readable statement. The second sentence gives use cases and update cadence. Every clause adds value.

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 no output schema, the description lists all key return fields, explains the computation basis, mentions the update frequency, and provides clear invocation context. The optional parameter's behavior is covered in the schema, so no gaps remain for a tool of this complexity.

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?

The schema documents the only parameter 'days' with a full description and 100% coverage, including the Gold tier requirement and optional history behavior. The tool description adds no extra parameter semantics, so the baseline score of 3 applies as the schema handles the parameter documentation.

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 uses a specific verb 'Returns' and names an exact resource, 'advanced-therapeutics research-velocity score', with a clear definition based on Europe PMC publication counts. It distinguishes itself from the many sibling tools by listing the specific modalities (gene therapy, CAR-T, mRNA, GLP-1) and output fields, making its scope unambiguous.

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 states 'Call when the user asks whether biotech research is accelerating, which modality is heating up, or when timing pharma R&D, licensing, or biotech allocation decisions.' This gives direct, concrete use cases and even provides context for alternative decisions, though it doesn't name alternative tools.

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