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

With no annotations, the description must carry the transparency burden. It usefully discloses that the tool uses ICD-10-GM and is limited to common codes and chapter overview, which are meaningful constraints. However, it does not describe output format, error handling, or behavior when both 'code' and 'search' are provided.

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 two short sentences, front-loaded with the core purpose, and contains no filler. Every clause adds information: the action, the resource, the coverage scope, and the German modification.

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?

The tool is relatively simple with two optional parameters and no output schema, but the description omits expected output/return behavior and the relationship between code and search. It covers scope and language variant, yet an agent might still be uncertain about what to expect when invoking it.

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 the parameters are already documented. The description does not add extra usage details about code/search syntax, response format, or interaction between parameters, which is acceptable at the baseline.

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 ('lookup and search') and resource ('ICD-10 code'), making the tool's purpose immediately clear. It also adds scope ('common codes and chapter overview') and locale ('ICD-10-GM'), which helps differentiate it from the unrelated sibling regulatory tools.

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 clear context that this tool is for ICD-10 code lookup/search and clarifies its scope (common codes, chapter overview). It does not explicitly name alternatives or exclusions, but no sibling tool offers similar functionality, so the usage context is clear.

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