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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the description's added value is the operational context: 24-hour cache, no charge against the estimate allowance, and null means not available. Missing only failure behavior when a carrier is not found.

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?

Front-loaded with the core action and return contents, and every sentence carries information (data source, output pairing, null semantics, identifier choice, cache, quota). Slightly dense as a single block but no filler.

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?

With no output schema, the description carries the return-value burden and does so well by listing the data categories and the FreightFA report contents. The gap is ambiguity around name searches returning multiple matches and the not-found case.

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?

Schema coverage is 100% and each param is documented, so baseline would be 3. The description adds genuinely new meaning: only one of the three identifiers should be supplied, which resolves the schema's otherwise confusing requirement of all three.

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?

States a specific verb and resource ("Vet a U.S. motor carrier from FMCSA SAFER data") and enumerates the returned dimensions: authority, safety rating, insurance, out-of-service rates, and the FreightFA report. No sibling tool performs carrier vetting, so the agent can confidently route here.

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?

"Search by USDOT number, MC number, or carrier name (give one)" tells the agent how to invoke it, and the vetting framing implies the pre-qualification use case. It stops short of explicit when-not-to-use or alternative routing, though no sibling overlaps.

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