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

With no annotations, the description must carry the behavioral burden, and it does disclose the output contract (allow/review/block with scores and reasons) and a constraint (free sample). It omits operational details such as rate limits beyond the sample tier, whether submitted text is logged or retained, and latency, but for a stateless analysis tool the essentials are present.

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?

Four short sentences, each doing distinct work: scope, threat classes, return values, and routing. The 'Free sample.' opener is slightly cryptic as a lead and the tier limitation is only fully clear once the schema is read, but nothing is redundant.

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 exists, yet the description explains the return shape (three verdict levels with scores and reasons), which is what an agent most needs. Combined with the routing guidance and single well-documented parameter, only minor operational details are absent.

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?

One parameter with 100% schema description coverage, so the schema already defines 'text' and its 4000-character free-sample cap. The description adds only a selection heuristic ('text you did not write'), which is useful framing but not syntax or format detail beyond the schema. Baseline 3 applies.

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 (check) plus the exact resource (untrusted text such as web pages, emails, documents, tool output) and enumerates the threat classes it detects. It also names the sibling it is not (verdict_firewall), so an agent can route without opening any schema.

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?

Explicit trigger ('before your agent reads untrusted text'), explicit scope ('use it on text you did not write'), and an explicit exclusion with the correct alternative ('Do not use it to judge an action: use verdict_firewall'). This is a full when/when-not/alternative statement.

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