ONES Doc MCP

Download ONES Resource

download_ones_resource

Read-onlyIdempotent

Fetches an ONES resource by URL, enabling retrieval of document files or images when signed links expire.

Instructions

Download an ONES resource by URL. Signed image URLs can expire; prefer get_doc(include_resources=true) followed by download_ones_resource_by_id.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes

Output Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes
`filename`	Yes
`mime_type`	Yes
`size_bytes`	Yes
`content_base64`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedv2.1.0Oct 5, 2026

removedOutput schema / properties / filename / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / filename / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / mime_type / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / mime_type / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Addedv1.5.0Jun 21, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds a genuinely useful behavioral trait beyond them: signed image URLs can expire, which explains why failures occur and points at a workaround.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, zero waste, with the core action front-loaded and the fallback guidance immediately after.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists so return values need no explanation, and annotations cover the safety profile. For a one-parameter read tool the description covers the main operational pitfall (expiry); only URL format specifics are absent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Only one parameter (url) with 0% schema description coverage, so the description carries the burden. 'By URL' implies an ONES resource URL but gives no format, accepted schemes, or whether it must be signed or freshly obtained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Download an ONES resource by URL') and implicitly distinguishes itself from the sibling download_ones_resource_by_id by naming the URL-based access path. Clear enough for an agent to pick between the two, though it doesn't spell out the difference explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly recommends an alternative path when signed URLs may be stale: 'prefer get_doc(include_resources=true) followed by download_ones_resource_by_id.' That is concrete when-to-use-other guidance, but the condition triggering the switch ('can expire') is stated loosely rather than as a hard rule.

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