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

Annotations already declare the operation as read-only, idempotent, and non-destructive. The description adds useful context by citing the data source and noting that filters are applied by the SFDA server. It does not describe pagination behavior or data freshness, but annotations lower the burden.

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 compact and front-loaded with the core purpose, followed by the field list and source. Both sentences earn their place, and there is no redundant wording or repetition of 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?

The description lists the returned fields, which is important since there is no output schema. It covers the source and server-side filtering. It does not explain how multiple filters combine or the meaning of the variable page size, but the schema handles page details and the tool is a straightforward filterable list.

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 covers 100% of the parameters with descriptive text, so the description need not repeat them. The phrase 'Filters are applied by the SFDA server' adds minimal context about how the parameters behave. No additional parameter semantics are provided beyond the schema.

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 identifies the resource (clinical trials registered with the SFDA in Saudi Arabia) and lists the key fields returned. It does not use an explicit verb like 'search' or 'list', but the meaning is clear. It is distinguishable from the sfda_drug_* siblings by the clinical-trials scope, though it does not name them.

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?

No guidance is given about when to use this tool versus related tools such as sfda_drug_search or sfda_drug_approvals. The intended context is implied by the resource name and fields, but there are no exclusions or alternative tool references.

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