Upload media to WordPress from an external URL and import remote files into the media library. Set title, caption, alt text, and filename during upload.
Upload media to WordPress from an external URL
| Name | Required | Description | Default |
|---|---|---|---|
| alt | No | Alt text (for images) | |
| url | Yes | URL of the file to download and import | |
| site | Yes | Site id (see list_sites) | |
| title | No | Media title | |
| caption | No | Caption | |
| filename | No | Override filename |
Changes observed during successful MCP inspections.
v3.4.0Input schema / properties / siteAdded value: +{
+ "description": "Site id (see list_sites)",
+ "type": "string"
+}Input schema / requiredPrevious value: -[
- "url"
-]New value: +[
+ "site",
+ "url"
+]v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It says 'Upload' but does not disclose side effects, required permissions, whether existing media can be overwritten, how the remote download is handled, or what happens on failure.
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?
A single front-loaded sentence with zero waste. It communicates the core action and source efficiently, and no sentence fails to earn its place.
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 six-parameter mutation tool with no annotations and no output schema, the one-sentence description is insufficient. It leaves behavioral expectations, side effects, and failure modes completely unspecified, relying on the schema only for parameter names.
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%, so all six parameters are already documented in the schema. The description adds no parameter-level detail beyond the schema, making the baseline of 3 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 ('Upload'), resource ('media'), and source ('from an external URL'), making the tool's core action clear. It does not explicitly name or distinguish itself from siblings like wp_update_media, but the external-URL source provides strong differentiation.
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 phrase 'from an external URL' implies the primary use case, but there is no explicit when-to-use guidance, no prerequisites, and no comparison to alternative media tools. Usage is inferable but not spelled out.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.