Fetch OSV vulnerability records for a specific package version, then paginate with next_page_token until has_more is false to collect complete results.
Fetch one OSV page for a package version. Repeat with next_page_token until has_more is false.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| version | Yes | ||
| ecosystem | No | npm | |
| page_token | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered structurally. The description adds the genuinely useful fact that results are paginated and must be drained via a token, which is behavior beyond the annotations — but it calls the parameter 'next_page_token' while the schema names it 'page_token', which is a naming inconsistency an agent could misread.
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?
Two short sentences, zero filler, with the pagination constraint placed after the core action. Nothing extraneous and nothing buried.
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?
An output schema exists and the annotations cover the safety profile, so the description needn't explain return values. But with four parameters and zero schema documentation, leaving 'ecosystem' entirely unexplained and misnaming the page token leaves gaps an agent must guess through.
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 0%, so the description carries the full burden, and it only gestures at name/version ('package version') and the page token — the latter under the wrong name. The 'ecosystem' parameter, which defaults to npm and materially changes results, is never mentioned in the description or the schema.
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?
The description states a specific verb and resource ('Fetch one OSV page') and scopes it to 'a package version', so the agent knows this is a single-page vulnerability lookup rather than a batch or CVE-database query. It stops short of naming which sibling to use instead (osv_vuln, osv_batch, nvd_cve), so the differentiation from the sibling list is only implicit.
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?
The second sentence gives a real usage rule — loop until has_more is false — which tells the agent this tool returns partial results. However, there is no guidance on when to pick this over osv_batch or osv_vuln, and no statement of what happens if the package is unknown or the ecosystem is omitted.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.