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

No annotations are present, so the description bears the burden of behavioral disclosure. It explains the OR-semantics for interventions and the default fields via SEARCH_TOOL_DEFAULTS, but it does not mention read-only status, potential errors, or output structure. These are useful but not fully comprehensive; a search tool implies read-only, yet this is not explicitly stated.

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 well-structured with an intro and bullet-point-style parameter explanations. It is reasonably concise, though it slightly repeats 'intervention/treatment' and could be tighter. The example and defaults list are valuable, so it earns a high score for structure without being overly verbose.

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?

With no output schema, the description should explain return values. It partially does by naming the default return fields, but it does not describe the result container or pagination. Given the tool's simplicity, this is adequate but leaves gaps for an agent trying to consume results. It is complete enough for basic use but lacks full contextual details.

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 is 100%, so baseline is 3. The description adds meaningful value beyond schema by clarifying that multiple interventions are matched using OR, providing an example for the interventions parameter, and explicitly listing the SEARCH_TOOL_DEFAULTS fields when fields is not provided. This goes beyond the schema's simple parameter names.

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 'Search clinical trials by intervention/treatment' with a specific verb and resource, and distinguishes it from sibling tools like search_trials_by_condition and search_trials_by_sponsor by explicitly naming the search dimension (interventions).

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 provides clear context on usage—it searches for trials matching any of the provided interventions, with defaults for max results and return fields. However, it does not explicitly mention alternative tools or exclusions (e.g., 'use this instead of search_trials_by_condition'), so it lacks the when-not-to-use guidance for a top score.

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