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

Annotations already cover read-only, open-world, idempotent, non-destructive behavior. The description adds useful context: dates are sponsor-entered, may be estimated or revised, and are not guaranteed data readouts, conference presentations, or regulatory events. This goes beyond the annotations and helps calibrate expectations.

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?

Two sentences: the first states the core function, the second provides an important interpretative caveat. No filler, no repetition of schema details, and the most action-relevant information is 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?

For a tool with 9 parameters, no output schema, and many clinical-trial siblings, the description gives the essential purpose and an important caveat, but it does not provide routing guidance against sibling tools or explain what the returned trials contain. The schema covers parameter mechanics, but the description alone leaves some contextual gaps for an agent deciding between this and related ct_* tools.

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 56%, with descriptions for query, sponsor, date range, and sponsor_match. The description adds semantic weight to the date/event parameters by clarifying that these are sponsor-entered planning signals that may be revised, but it does not meaningfully explain limit, phase, or status parameters. It contributes some value but does not fully compensate for the un-described parameters.

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?

States a specific verb and resource: finding trials with sponsor-entered primary-completion or study-completion dates within a window. The caveat about planning signals versus confirmed readouts/conference/regulatory events helps distinguish it from event-focused sibling tools, even though no sibling is named.

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 this tool is for planning-signal date windows and warns against treating the dates as guaranteed events, but it does not explicitly say when to use this tool versus alternatives like ct_search or ct_results_summary. No named alternative or exclusion condition is provided.

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