versionOne published release of a deno.land/x module: when it was uploaded, the GitHub repository and ref it was published from, and the full file listing for that version.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| version | Yes | e.g. "v17.2.0" — call versions first if unsure. |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Input schema / properties / version / descriptionAdded value: +"e.g. \"v17.2.0\" — call versions first if unsure."Input schema / examplesAdded value: +[
+ {
+ "name": "std",
+ "version": "0.208.0"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Single version metadata from deno.land/x registry",
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds value by describing what the response contains (upload time, repository, ref, file listing), which informs the agent about expected output beyond the annotations. It does not contradict annotations and provides useful behavioral context about the returned data.
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 description is a single, well-structured sentence that front-loads the core purpose ('One published release of a deno.land/x module') and then lists the specific data fields. Every word earns its place; no filler or redundancy. It is appropriately sized for the tool's simplicity.
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?
For a read-only lookup with two parameters and an output schema, the description adequately covers what the tool does and what it returns. It does not mention error handling or how to find the correct version, but that is partially addressed by the schema hint. The presence of an output schema reduces the need to explain return values. Overall, it is complete for a tool of this complexity.
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?
The schema covers the 'version' parameter with an example and a hint to call 'versions' first, but 'name' lacks a description. The tool description implies 'name' refers to a module name, but does not explicitly define it or add details beyond the schema. With 50% schema coverage, the description partially compensates by contextualizing the tool as a deno.land/x module lookup, but the 'name' parameter remains underspecified.
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 clearly states the tool returns a single published release of a deno.land/x module, specifying exactly what data is included (upload time, GitHub repo, ref, file listing). It distinguishes itself from the plural sibling 'versions' by focusing on one version, making its purpose unambiguous.
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 description implies usage for a specific version, but it does not explicitly state when to use this tool versus the 'versions' tool for listing all releases. The schema hint for the 'version' parameter suggests calling 'versions' first, but that guidance is not in the description itself. The usage context is implied but not directly stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.