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

Beyond the readOnlyHint annotation, the description adds significant behavioral context: data source (ClinicalTrials.gov snapshots), update frequency (monthly since 2010), the weighted-share methodology, and the Gold-tier requirement for the history parameter. It also clarifies the fallback to the current snapshot, providing solid transparency.

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 compact yet comprehensive, with two sentences that front-load the result, explain the index composition, list output fields, and provide usage triggers. Every sentence earns its place with no redundancy.

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?

Given the tool's simplicity (one optional parameter, no output schema), the description covers all essential information: what the index means, how it is calculated, what fields are returned, update frequency, and when to use it. It is self-sufficient and complete.

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 coverage for the only parameter (days) is 100%, including optionality, range, Gold-tier requirement, and fallback behavior. The description adds no additional parameter semantics beyond what the schema already provides, 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?

The description clearly states the tool returns a Clinical Trial Complexity Index with specific components (score, trend, top_drivers, methodology_version), defines the 0-100 scale, baseline of 50, and data source. It uses a specific verb-resource pair and is distinct enough from siblings.

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 explicitly lists when to call the tool ('asks about clinical-trial landscape complexity, trial design trends, or CRO capacity pressure') and business contexts ('site-selection bids, site fees, or recruitment strategy'). It does not mention exclusions or alternative tools, so it falls 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.