hud_list_metro_areas

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds the useful fact that returned codes are entity_id values for HUD tools, but it does not disclose other behavioral details such as output fields or whether the list is exhaustive.

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?

Two sentences, no wasted words, and the core action is front-loaded. The second sentence earns its place by connecting the output to downstream HUD tool usage.

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 parameterless list endpoint, the description is mostly complete: it states what is listed and why the output matters. It could be marginally clearer about what fields are returned, but the CBSA-code-as-entity_id note largely compensates for the missing output schema.

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 tool has zero parameters, so there is nothing for the description to explain beyond what the empty schema already communicates. The baseline for zero parameters is 4, and the description appropriately does not invent unnecessary parameter guidance.

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 uses a specific verb ('List') and identifies the resource ('metropolitan/CBSA areas'), and it adds a valuable cross-tool note that CBSA codes serve as entity_id values. It does not explicitly distinguish this from sibling HUD list tools like hud_list_states or hud_list_counties, but the scope is clear enough from the name and content.

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 for when this tool is useful: when an agent needs CBSA codes to pass as entity_id into other HUD tools. It does not mention when to avoid it or name alternatives, but for a simple zero-parameter list tool the use case is well implied.

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