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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description still adds real behavioral context the annotations cannot convey: partial name matching is supported, results are capped at 50, and the source is the FMCSA national database. Only the no-match/empty-result behavior is left unstated.

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 purpose, then capabilities, then example queries, then return shape and cap — a sensible order with no filler. The example-question list is slightly long for a one-parameter search tool, but each example demonstrates a distinct phrasing pattern an agent may encounter.

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 burden and does so by naming the returned fields (DOT number, MC number, location, fleet size, operating status) and the 50-result cap. What remains uncovered is behavior on zero matches and whether results are ranked, which matters for a fuzzy name search.

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% with a single documented 'name' parameter, so the baseline is 3. The description earns the extra point by disclosing that matching is partial rather than exact, which materially changes how an agent should form the query and is not stated in the schema.

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 (search) and resource (trucking companies / freight carriers / motor carriers) plus the entity type it resolves (carriers in the FMCSA database). It is clear on its own, but it never distinguishes itself from close siblings like fmcsa_carrier_lookup or fmcsa_carrier_authority, so an agent must infer that this is the name-based entry point versus the DOT-number-based one.

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 'Use this for questions like...' list gives concrete trigger phrasings ('what's the DOT number for Werner?', 'search for freight carriers in Texas'), which is strong positive guidance. What is missing is the exclusion side: no statement such as 'if you already have a DOT/MC number, use fmcsa_carrier_lookup instead', even though that sibling exists.

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