Check a number's community reputation

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

With no annotations, the description carries the full burden. It discloses the unverified, crowd-sourced nature and the spoofing warning, but does not mention whether the tool is read-only, has rate limits, or data freshness. The behavioral traits beyond the core output are under-specified.

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 wasted words. The most important information (the return values and meaning) is front-loaded, and the caveat is provided immediately after.

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 single-parameter tool with no output schema and no annotations, the description covers the return value meaning and critical caveats. It lacks potential details like cost or async behavior, but given the simplicity, it is fairly 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 coverage is 100% with a clear example and format. The description adds no new parameter-level details beyond the schema, so it meets the baseline of 3 but does not exceed it.

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 returns an UNVERIFIED crowd-sourced signal for US/Canada numbers, defines the possible values ('low', 'mid', 'high'), and explains their meaning. The verb 'Return' and scope are explicit, distinguishing it from sibling tools like area code or carrier lookups.

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 good usage context by noting that the signal is unverified and that caller ID can be spoofed, implying the tool should not be used as proof of fraud. However, it does not explicitly state when to use it versus when to avoid it, nor name alternative tools for definitive checks.

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