Clinicaltrials Get Field Definitions

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description does not need to restate that. It adds behavioral context by explaining that search returns ranked matches, drill returns a section's fields, and overview gives a summary. This goes beyond the annotations without contradicting them. Minor omission: no mention of pagination or rate limits, but for a read-only helper that's acceptable.

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 moderately long but every sentence carries information: purpose, examples, and mode breakdown. It is logically structured, starting with the core purpose, then detailing modes. No filler or repetition exists. It could be slightly tightened, but it remains efficient and 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 tool's moderate complexity (5 parameters, 3 modes) and the presence of an output schema, the description covers all necessary aspects: what the tool returns, which modes exist and when to use them, and how it fits into the broader toolset. It does not miss critical details for an agent to correctly invoke it. Slight gaps like not describing error behavior are negligible for a read-only helper.

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 parameters are well-documented in the schema. The description adds value by providing concrete examples for query ('enrollment', 'sponsor'), clarifying which parameters apply to which mode, and giving a sample dot-notation path for drill. This supplements the schema without redundancy, justifying a score above the baseline 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 states a specific purpose: resolving valid field names from the ClinicalTrials.gov data model, with concrete examples of PascalCase identifiers. It clearly explains that these names are used as inputs to other tools, distinguishing it from siblings that retrieve data or search studies. The verb 'resolve' and resource 'field definitions' are precise.

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 says when to use this tool: to obtain field names for the 'fields', 'advancedFilter', and 'sort' parameters of other tools, and as input to clinicaltrials_get_field_values. It also details the three operational modes with conditions (e.g., search requires query, drill requires path, overview needs no args). This is clear, actionable guidance with no ambiguity.

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