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

No annotations are provided, so the description carries the full burden and does well: it discloses cost ('FREE'), the authoritative data source (Health Canada-authorised), the result limit (5), and the sort order (newest first). It omits whether keyword matching is exact or partial and says nothing about auth or rate limits.

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?

One compact sentence with the cost signal front-loaded and the scope, source, and limit packed in without waste.

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 one-parameter, no-output-schema, no-annotation tool, the definition covers cost, source, count, and ordering. The remaining gap is how results are selected and matched, which matters somewhat for a search tool.

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 0% for the single keyword parameter, so the description must compensate. It does clarify that the keyword may be either a condition or a drug name, which the bare 'string' schema does not, but adds no detail on matching behavior, brand vs generic names, or partial terms.

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: Health Canada-authorised clinical trials searched by condition or drug keyword, capped at the newest 5. The result cap implicitly separates it from trial_search_full, though the sibling is never 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?

It gives a use context ('for a condition or drug keyword') but never states when to prefer trial_search_full or trial_detail. The 'newest 5' cap hints at the alternative without saying so explicitly.

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