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

The description states 'Read-only: the file is never modified,' which aligns with the annotations (readOnlyHint=true, destructiveHint=false). It also discloses behavior beyond the annotations by specifying what it scans for and what it returns.

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 concise—two sentences—and well-structured. It states the purpose, the scope, and the output without any unnecessary verbiage.

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 tool with one parameter and no output schema, the description is complete. It explains what the tool does, what it scans for, what it returns, and its read-only nature, providing all necessary context for an agent to use it correctly.

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 schema already provides a clear description for the single parameter 'filepath' ('absolute path of the file to scan'). The tool description does not add significant extra meaning beyond the schema, so it meets the baseline for 100% schema coverage.

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?

Clearly states it security-scans a single file, lists the specific categories it checks (invisible Unicode, dangerous patterns, secrets), and describes the output (severity-weighted score and per-finding details). This fully distinguishes it from the sibling tool trust_scan_server which presumably scans a server.

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?

Explicitly says 'single file' which differentiates from trust_scan_server, but does not explicitly say 'use this for single files, use trust_scan_server for servers.' However, the scope is clear enough for an agent to infer the correct use case.

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