hud_list_counties

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

The annotations already declare readOnlyHint=true, so the description does not need to repeat that. The description adds the purpose but does not disclose any additional behavioral traits such as rate limits, data freshness, or specific output format. Given the annotation coverage, a score of 3 is appropriate.

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 sentences long, front-loaded with the core purpose, and every sentence adds value (purpose + usage guidance). No wasted words.

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 description states the purpose and links to related tools but lacks information about the output structure (e.g., list of objects with fields). Since there is no output schema, the agent might need to infer the format. It is minimally complete for a simple list tool but could be improved.

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 provides a full description of the 'state' parameter with examples. The description does not add any additional meaning beyond what is already in the schema. With 100% schema coverage, baseline is 3.

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 verb 'list' and the resource 'counties in a state with their FIPS codes'. It also distinguishes itself from sibling tools by specifying how the output (FIPS codes) should be used with hud_fair_market_rents and hud_income_limits, which are present in the sibling list.

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 explicitly directs the agent to use the FIPS codes as entity_id in related HUD tools, providing clear context for downstream usage. However, it does not mention when not to use this tool or offer alternatives.

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