Verifreta Carrier Lookup

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly indicates a read-only operation ('remaining free lookups') with no side effects, which is transparent enough. It also clarifies the client scope (IP or signed-in account), which is useful context. It could be slightly more explicit about being non-destructive, but the phrasing strongly implies it.

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 short sentences with zero filler. The core purpose is front-loaded, and the second sentence adds essential context about the shared pool. Every word earns its place.

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 tool with no parameters and no output schema, the description fully explains what the tool does (returns remaining free lookups), who it applies to (the client), and how the quota is shared across lookup types. An agent has all the information needed to call it correctly and interpret the result (a number).

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 tool has zero parameters, so the schema coverage is effectively 100%. Baseline for no-parameter tools is 4. The description adds no parameter-specific details because there are none to describe. It correctly focuses on the output and scope instead.

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 tool's purpose: returning the remaining free MCP lookups for the client. It names the specific resource (free lookups) and scope (per IP or signed-in account), and it implicitly distinguishes itself from the sibling lookup tools (which perform lookups, not quota checks). No ambiguity.

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 explains that the quota is a shared pool for USDOT, MC/MX/FF, and name search, which hints that it applies to all sibling lookups. However, it does not explicitly state when to use this tool (e.g., before performing lookups) or when not to use it. The guidance is implied rather than explicit.

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

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

With no annotations, the description carries the full behavioral burden. It discloses that the lookup is free, is a 'first look' (implying limited detail), uses the FMCSA QCMobile path, and counts against a trial quota. However, it does not mention error behavior, rate limits, or the exact return structure beyond listing fields. Some context is added, but gaps remain.

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 a single, efficient sentence that front-loads the core purpose ('Free USDOT / DOT carrier first look') and then lists fields and quota impact. It is concise without unnecessary fluff, though it packs several details into one sentence.

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 simple one-parameter lookup with no output schema, the description adequately covers what the tool returns (legal name, allowed-to-operate, fleet, dockets, cargo, authority) and notes the trial quota. It could mention error conditions or what happens on invalid numbers, but these are minor omissions given the simplicity.

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 description coverage is 100%: the query parameter is fully described with format rules (digits only, optional prefix stripped). The tool description adds no extra meaning beyond that, so the baseline 3 is appropriate since the schema does the heavy lifting.

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 tool's function: a USDOT carrier lookup. It specifies the resource (USDOT/DOT number) and the verb ('lookup'), and lists the returned census fields. The title and description together distinguish it from siblings like lookup_mc and lookup_name by the identifier type.

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?

Usage is implied by the name and description (use when you have a USDOT number), but there is no explicit guidance on when to prefer this over lookup_mc or lookup_name, nor any exclusions. The quota note ('Counts 1 toward the shared 5-lookup MCP trial') provides context on shared limits but doesn't direct tool selection.

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

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

With no annotations, the description carries the full burden. It discloses that the tool is 'Free' and that it 'Counts 1 toward the shared 5-lookup MCP trial', which is important for quota management. It also implies a limited 'first look' behavior. However, it does not clarify whether the operation is read-only, what happens on invalid input, or the exact nature of the returned data. The quota disclosure adds value, but other behavioral aspects are left unspecified.

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 three concise sentences with no redundant phrasing. The main purpose is front-loaded in the first sentence, input format is in the second, and quota impact in the third. Each sentence earns its place, and the overall length is appropriate for a simple lookup tool.

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 tool has no output schema, so the description should clarify what the agent can expect as a return. 'Carrier first look' suggests a preview of carrier information, but it does not explicitly state the return format or content. The quota information is useful, but for a lookup tool with one parameter, a bit more detail about the output would improve completeness. Given the simplicity, the description is adequate but not fully complete.

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 description coverage is 100%, with the parameter 'query' documented as 'Docket number with MC, MX, or FF prefix (e.g. MC-123456)'. The description's mention of 'Accepts MC-123456 or prefixed docket input' essentially repeats this information, adding no new semantic detail. The baseline of 3 applies because the schema already covers the parameter.

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 states a specific action ('carrier first look') and resource ('MC, MX, or FF docket'), clearly distinguishing this from sibling tools lookup_dot and lookup_name which likely handle DOT numbers and carrier names. The title and name reinforce this, making the purpose unambiguous.

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 provides no explicit guidance on when to use this tool versus lookup_dot or lookup_name. The only contextual hint is the mention of 'same path as verifreta.com/tools/mc-number-lookup', which is an external URL and not useful for an agent. No exclusions or alternative routing are given.

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

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

No annotations are provided, so the description carries the full behavioral burden. It discloses useful non-obvious traits: returns up to 10 matches, empty results do not consume a credit, and successful matches count toward the shared 5-lookup MCP trial. It does not describe response field shapes or failure modes, but for a simple lookup tool this is adequate.

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?

Three compact sentences, each earning its place. The first sentence front-loads the operation and endpoint, while the next two add only non-obvious behavior around match limits and quota consumption. There is no filler or redundant restating of the schema.

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 single-parameter lookup with no output schema and no annotations, the description adequately covers input, expected result count, and credit/trial behavior. It stops short of describing the exact shape of a match or explicitly routing to sibling tools, but those are minor gaps for successful 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?

Schema coverage is 100%, and the query parameter is already described as a legal or DBA name fragment with length constraints. The description reinforces that this is a name search against the FMCSA endpoint but does not add new parameter-level details such as formatting, wildcard behavior, or normalization rules. Baseline 3 is appropriate.

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 identifies a specific verb and resource: searching carrier legal or DBA names via the FMCSA census name endpoint. It also states that it returns up to 10 matches, which helps distinguish it from identifier-based lookups like lookup_dot and lookup_mc, though it does not explicitly name those siblings.

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 gives clear context for when to use the tool: when searching by legal or DBA name fragment. It also communicates the no-credit-on-empty-results behavior and the trial quota usage. However, it does not explicitly state when not to use it or steer the agent toward lookup_dot/lookup_mc for DOT/MC number lookups.

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