list_units

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

No annotations are provided, so the description must convey behavior. It states this is a list operation and implies read-only, but does not clarify the exact output structure (e.g., list of strings vs. objects) or the effect of the optional domain parameter default. The examples hint at content but not the response envelope.

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 a single sentence plus examples, with no wasted words. It is front-loaded with the core action and resource, making it easy to scan and understand.

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 optional parameter and no output schema, the description provides the essential purpose and examples of the expected unit values. It does not specify the exact JSON response format, but the list nature and examples make it adequate for basic invocation.

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 only parameter 'domain' is already well-described in the schema as a BPS domain code with a default of '0000'. The description adds that units are domain-scoped but provides no additional syntax or format details. With 100% schema coverage, the baseline score of 3 is appropriate.

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 that the tool lists data units for a given domain, with concrete examples (Person, Percent, Rupiah). This distinguishes it from sibling list tools like list_census_areas or list_variables, making the purpose unambiguous.

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 clearly indicates the intended use case—retrieving available measurement units for a specific domain. It does not explicitly mention alternatives or exclusion criteria, but the examples and domain scoping make it clear when to use this tool versus other list tools.

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