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

Adds two facts the annotations cannot convey: the result is a heuristic, not a definitive malware verdict, and the call costs $0.01 USDC per successful call via x402 on Solana. It also discloses an equivalent no-cost-gateway HTTPS path. For a paid, open-world network call this is exactly the extra context an agent needs.

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?

Front-loads the identity and signal list, then the limitation, then the cost and endpoint. Three compact units, no restatement of the name or title, and every clause carries information an agent would otherwise lack.

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 carries the burden of telling the agent what comes back, and it does so by enumerating the risk signals. Two simple parameters, annotations covering the safety profile, and explicit cost — nothing an agent needs in order to call it correctly is missing.

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% for both required parameters, so the schema already defines 'name' and 'ecosystem' (npm or pypi). The description only adds the incidental note that weekly-download data is npm-specific, which is a useful but thin addition beyond structured fields — 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?

Names a specific verb+resource ('npm or PyPI package risk/typosquat check') and enumerates the exact signals it returns: registry metadata, weekly downloads, deprecation, license/repo presence, edit-distance, and existing close-name variants. The explicit 'Heuristic — not a malware scanner' boundary separates it from sibling security tools like osv_scan and sol_token_risk.

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 enumerated signals — an agent infers this is the typosquat/license/metadata check rather than a CVE scan — but there is no explicit 'use this instead of osv_scan when...' routing and no prerequisites stated. The only explicit guidance is about access path (HTTP endpoint) and price, not tool selection.

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