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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, destructiveHint. Description adds that data is a statewide snapshot refreshed monthly, specifies plug-in hybrid labeling, and confirms returned total is whole fleet. No contradiction.

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?

Description is somewhat long but front-loads purpose, then provides details and sibling differentiation. Every sentence adds value; minor verbosity is acceptable given complexity.

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?

No output schema, but description explains output (statewide row per fuel type), data source (Delaware DMV), and refresh frequency (monthly). Covers all necessary context for selection and 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?

Single parameter fuel_type with 100% schema coverage. Description adds context: lists all fuel types including 'Other (Or None)' and explains plain words map to Delaware's labels, e.g., 'plug-in hybrid'.

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?

Description clearly states it counts vehicles by fuel type from Delaware DMV snapshot, provides example questions it answers, and distinguishes from siblings like de_dmv_ev_adoption and de_dmv_ev_rebates.

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?

Explicitly lists queries it answers ('how many vehicles are registered in Delaware') and says when to use alternatives ('for EV share use de_dmv_ev_adoption; for rebates use de_dmv_ev_rebates').

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