Check a single package name against the real npm or PyPI registry to detect slopsquatting and dependency confusion before installing it.
Check a single package name against the real npm or PyPI registry
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Package name | |
| ecosystem | Yes | Which registry to check |
Changes observed during successful MCP inspections.
v0.1.5Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. Saying 'the real ... registry' hints at a live network call, but nothing is said about rate limits, what happens for a non-existent or unreachable registry, whether results are cached, or what 'check' actually evaluates (existence alone versus typosquat/hallucination risk).
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?
One front-loaded sentence with no filler or redundancy. It is efficient, though so terse that it leaves the tool's actual output and behavior underexplained rather than being genuinely complete.
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 only two simple required parameters and full schema coverage, the low complexity keeps a minimal description viable. However, with no output schema and no annotations, the description should at least indicate what a 'check' returns (existence verdict, risk score, advisory) and is silent on that.
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 description coverage is 100% with an explicit enum for ecosystem, so the schema already documents both parameters fully. The description merely echoes them ('package name', 'npm or PyPI') without adding naming rules, scoped-package syntax, or case sensitivity.
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?
Specific verb ('check') plus resource ('a single package name') and scope ('against the real npm or PyPI registry'), which implicitly separates it from the bulk siblings scan_npm/scan_pip/scan_directory. It stops short of naming those siblings, so an agent must infer the boundary from the word 'single'.
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 only implied: 'single package name' signals one-off lookups versus the directory/registry-wide scans in the same family. There is no explicit when-to-use, when-not-to-use, or pointer to scan_npm / scan_pip for bulk work.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.