clinical_trials_stats

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered. The description adds meaningful behavioral context beyond annotations: it 'queries 8 statuses in parallel for comprehensive breakdown,' which implies parallel calls and potentially higher latency or rate-limit impact. It also clarifies the nature of the output (counts by status, not a trial list). No contradictions with annotations.

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 four short, focused sentences. The main purpose is front-loaded, followed by output format, accepted inputs with examples, and a behavioral note. Every sentence earns its place with no fluff or repetition.

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 simple 2-parameter tool with no output schema, the description sufficiently explains what the tool returns (counts by status) and how it handles both condition and drug inputs. It does not detail the exact response structure or status list beyond 'etc.', but the general shape is clear. Annotations cover safety, so the description is nearly complete.

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% with both parameters already documented. The description adds example values ('breast cancer', 'semaglutide') and clarifies that condition can be a drug/intervention, but this mostly repeats schema guidance. It does not add significant meaning beyond the schema, so baseline 3 is appropriate.

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 verb+resource: 'Get trial count breakdown by recruitment status for a condition or drug/intervention.' It clearly differentiates from sibling tools like clinical_trials_search and clinical_trials_detail by focusing on counts by status rather than searching or detailing individual trials. The examples of diseases and drug names further clarify the scope.

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 implies when to use the tool (when a count breakdown by status is needed) and clarifies that it accepts both diseases and drug names. However, it does not explicitly mention alternatives or provide when-not-to-use guidance relative to siblings like clinical_trials_search or clinical_trials_by_location. The usage context is clear but not explicitly routed.

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