List California ALW counties

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

Annotations already declare readOnlyHint, openWorldHint=false, idempotentHint, and non-destructive. The description adds meaningful context beyond annotations: the explicit guarantee that it 'does not fabricate county waitlist values' — a valuable behavioral promise signaling data fidelity. With strong annotations covering the safety profile, this 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?

Two concise sentences that pack useful information: scope, count, data fields, and a fidelity guarantee. Front-loaded with the purpose. Slightly redundant that quantity (15) is conveyed, but it's a meaningful data point, not fluff. 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?

For a 0-parameter, list-type tool with strong annotations covering safety and openness, the description is complete. It explains what data is returned (counts, capacity) and adds the anti-fabrication guarantee. No output schema exists, so some detail on return structure would be nice but isn't essential for a simple list tool.

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?

Tool has 0 parameters and schema coverage is 100% (nothing to document), so the baseline of 4 applies. The description adds clarifying info about what the output includes (provider-record counts, licensed PEU capacity), which helps an agent know what data to expect without needing parameter docs.

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?

Specific verb+resource: 'List' all counties with participating ALW facilities. States the exact count (15), what data is included (provider-record counts, licensed PEU capacity), and explicitly notes a scope fact. Clearly distinguishes from siblings like get_county_summary which targets individual counties.

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 makes it evident this is a top-level enumeration tool (list all counties) versus siblings like get_county_summary (single county) or get_program_summary (program-level). While it doesn't explicitly name alternatives or exclusions, the listing semantics and sibling differentiation are clear enough for an agent to choose correctly.

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