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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds valuable behavioral details beyond annotations: it is keyless (no API key), matching is partial and case-insensitive, and it returns the strength and product for each match. It also gives a concrete example call, enhancing transparency.

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 well-structured and front-loaded: it starts with the core purpose, then examples, then matching details, and ends with an example call. Every sentence adds value—no filler. It is concise yet comprehensive, earning a top score.

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?

With only two parameters and no output schema, the description explains what the tool returns (strength and product) and the matching behavior. It does not mention ordering, pagination, or error cases, but for a simple query tool it is fairly complete. The keyless note and Canadian scope are also included. Minor gaps but overall sufficient.

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%, so both parameters are already documented. The description adds nuance beyond the schema: ingredient names are official and matched partially/case-insensitively, and limit has default/max values (though schema already mentions default 25, max 100). The description enriches the semantics with matching behavior, adding value.

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 the tool's specific function (find Canadian drug products containing a given active ingredient) with a clear verb and resource (Health Canada's Drug Product Database). It provides example queries and distinguishes itself from likely siblings by emphasizing the 'by ingredient' approach. The wording makes it unambiguous what the tool does.

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 gives clear context on when to use it (answers 'which Canadian drugs contain X') and notes Canadian authorisations only. However, it does not explicitly mention alternatives like health_canada_search_drugs or health_canada_drug_detail, nor does it state when not to use this tool. It provides good usage context but lacks explicit exclusions.

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