get_trial

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

With no annotations, the description must carry the behavioral disclosure burden. It explicitly states the tool reads a record, returns a full set of fields, and returns a not_found error for unknown IDs. It doesn't mention auth or rate limits, but for a read operation, the error behavior and return shape are the main transparency needs. The word 'Read' signals non-mutating behavior.

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 front-loaded with a one-sentence purpose, then usage guidelines, then an Args section, then a Returns section. It is cleanly sectioned and every sentence conveys needed information without filler. It's slightly longer than two sentences, but the structured layout keeps it scannable.

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 single-parameter tool with an output schema, the description covers all needed context: when to use it, what the parameter is, what is returned, and the error condition. It leaves no ambiguity about how to select or invoke the tool. The output schema handles detailed return values, so the description's summary list is sufficient.

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 input schema provides only a type and title for nct_id, with zero description coverage. The tool description compensates fully by specifying the exact format ('NCT followed by exactly 8 digits') and providing an example ('NCT04280705'). This is indispensable for correct invocation.

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 begins with 'Read one clinical trial in full', a specific verb and resource, and immediately states the scope (eligibility). It explicitly contrasts with search_trials by saying 'Use this after search_trials when a specific trial matters', which differentiates it from the sibling tool. The return-value enumeration further clarifies its role.

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?

It provides explicit when-to-use guidance: after search_trials for a specific trial, or whenever an NCT number is mentioned. This is a clear condition that routes the agent to the correct tool. It doesn't list exclusions, but naming the alternative and the trigger condition is sufficient.

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