verifyConfirm an npm package is real, healthy, and not risky before installing: guards against hallucinated or typosquatted names, deprecations and known advisories, and returns a safety verdict with its reasons and what was not checked. Checks the live registry. The cheap gate to call before every install; use evaluate when you need the full scores.
| Name | Required | Description | Default |
|---|---|---|---|
| package | Yes | npm package name to verify |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description goes further by stating it checks the live registry (network implication), that it is the cheap/lightweight gate relative to evaluate, and that the verdict includes both reasons and what was NOT checked. The last point is unusually honest about limitations. It stops short of describing verdict values or failure behavior, so 4 rather than 5.
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-loaded with the purpose and risk coverage, then closes with the usage rule and alternative in a short final clause. The opening sentence is compound and dense, but every clause (risks, live registry, verdict contents) earns its place. Minor trimming possible, no real waste.
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 return-value burden and does so: a safety verdict with reasons plus explicit disclosure of what was not checked. Combined with the live-registry note and the cheap-vs-full distinction against evaluate, an agent has everything needed to call 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?
A single parameter at 100% schema description coverage, so the schema already defines the npm package name and its pattern/length constraints. The description adds no syntax, scoping, or scoped-package guidance beyond the name itself. Baseline 3 is 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 (confirm/verify) and resource (an npm package), then enumerates the exact risks it screens for: hallucinated/typosquatted names, deprecations, and advisories. It also explicitly names the sibling it is not (evaluate), so an agent can route between them without opening either 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?
Gives a concrete cadence ('the cheap gate to call before every install') and names the alternative with the condition that selects it ('use evaluate when you need the full scores'). No exclusions are left to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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