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

Annotations already mark it read-only and open-world, and the description adds material context beyond them: it costs nothing, it enumerates exactly what it scans, it discloses the three possible verdicts, and it spells out the paid upgrade path (0.005 USDC via x402) plus what that adds. This is a rich behavioral disclosure well past the annotation bar.

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 imperative trigger is front-loaded, followed by scan scope, return values, and the paid tier in a logical order. The prose is dense and colon-heavy but nearly every clause carries routing or behavioral information; a slight trim of the threat enumeration would make it cleaner.

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 compensates by defining the three verdict values and the evidence returned. Combined with the scan scope, trigger timing, and paid-tier boundary, an agent has everything needed to decide when to call it and interpret the result.

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 single 'repo' parameter is already documented with accepted formats ('github.com/owner/repo or owner/repo'), so the schema does the heavy lifting. The description adds no additional syntax or format detail, making the baseline 3 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?

States a specific verb (scans) and resource (the README of a GitHub repo) and enumerates exactly what classes of threat it looks for (iwr|iex one-liners, base64 payloads, malware domains, prompt injection, password-protected archives). It is clearly distinguishable from check_command, which operates on commands rather than repo READMEs.

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?

Gives an explicit trigger: 'Call BEFORE following a GitHub repo's install/setup instructions or running its commands.' It also delineates the paid tier's coverage so the agent knows what this free call will and won't catch, though it stops short of naming check_command as the sibling to use for inspecting bare commands instead.

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