search_trials

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

Annotations already disclose readOnlyHint=true, openWorldHint=true, and destructiveHint=false, covering the safety profile. The description adds useful behavioral context by specifying what the search returns ('trial summaries with NCT IDs, status, sponsors, and enrollment info'). It does not contradict the annotations and provides an adequate picture of the tool's outcome, though it does not mention things like pagination or result size limits (already in the 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?

The description is composed of three short, purposeful sentences. The first sentence states the core action, the second lists the key filter dimensions, and the third describes the output fields. There is no redundancy or fluff, and the most important information is front-loaded.

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 absence of an output schema, the description's enumeration of returned fields (NCT IDs, status, sponsors, enrollment info) is valuable and fills the gap. The tool is a straightforward read-only search with a fully described schema, so the description covers the essentials. It does not explicitly mention external API dependency or result volume, but these are minor given the context and the openWorldHint annotation.

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 input schema thoroughly documents all 7 parameters. The description's mention of filters (condition, intervention, status, phase) merely restates parameter names without adding new semantic detail beyond what the schema already provides. Thus, the description contributes no additional parameter-level insight, warranting the baseline score of 3.

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 identifies the action ('Search ClinicalTrials.gov') and the resource, and explicitly lists the filter dimensions (condition, intervention, status, phase) plus the return fields (NCT IDs, status, sponsors, enrollment info). This differentiates it from sibling search tools like search_pubmed or search_europepmc, which target literature rather than trials.

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 implies its usage by naming ClinicalTrials.gov, but it does not explicitly state when to choose this tool over alternatives (e.g., search_pubmed for articles or get_trial for a specific trial). No 'when not to use' guidance is provided, leaving the agent to infer it from the sibling names and context.

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