check_icd_for_major_illness_eligibility

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

Annotations already declare this as a safe, read-only, idempotent operation. The description adds important behavioral context: the tool is 'Reference only' and confirmed eligibility requires a formal application with supporting documentation. 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?

Three sentences, each with clear purpose: first states what it does, second gives usage guidelines with bold cues, third adds a reference caveat and attribution. Front-loaded, no filler, well-structured for agent scanning.

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 tool with one parameter and no output schema, the description fully covers purpose, return content, usage boundaries, and important disclaimers. Sibling differentiations are clear, and the note about formal application adds necessary context for proper use.

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 already provides a thorough description for `icd_code` (required, case-insensitive, prefix-matching, examples). Schema coverage is 100%, so baseline is 3. The description adds minimal new detail beyond the schema, only restating 'single ICD-10 code'.

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 clearly states the tool's function as a reverse-lookup from ICD-10 code to Taiwan NHI major illness categories, listing specific return fields. It explicitly distinguishes from the sibling tool `lookup_major_illness` which performs the opposite direction.

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 provides explicit use cases ('when an agent has a diagnosis... before claim submission'), explicit non-use cases ('Don't use to browse all categories'), and a direct alternative (`lookup_major_illness` instead). It also specifies the opposite direction usage.

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