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

With no annotations provided, the description carries the full burden of behavioral disclosure, but it says nothing about side effects, return types, pagination, filtering behavior, or required permissions. It is essentially non-informative about 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 very short, but this is under-specification rather than good conciseness. It lacks key information and does not front-load useful context; the few words used are vague and partially redundant with the tool name.

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 tool with 3 parameters (one required), no output schema, and no annotations, the description is entirely insufficient. It fails to explain what the tool returns, how parameters affect results, or any practical usage context, making correct invocation nearly impossible.

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 0%, and the description does not compensate. 'Brazil filter' vaguely hints at in_brazil_only, but there is no explanation of orphaCode, limit, or the interaction between parameters. The agent is left without meaningful parameter semantics.

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 'Trials ativos com filtro Brazil' is a fragment with no clear verb, essentially restating the tool name 'find_active_trials' and adding an ambiguous 'Brazil filter' reference. It does not specify what the tool does (e.g., find, list, search) or what the output represents.

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?

There is no guidance on when to use this tool versus alternatives. The sibling tools (e.g., find_reference_centers, find_phenotypically_similar) are not mentioned, and no context or exclusions are provided.

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