Postfjord

List media

postfjord_list_media

Read-only

Images and videos in the media library, newest first: id, kind, status (processing, ready or failed, with the error), name, alt text, size in bytes, width and height, durationSec for a video, and a thumbnail URL for a picture (a video has none yet). Use the ids as mediaIds.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "postfjord_list_media"
  }
}

Input Schema

Name	Required	Description	Default
`limit`	No	How many files at most.
`status`	No	Only files in this state. ready: the ones a post can use now.

Output Schema

Name	Required	Description	Default
`items`	No	The files, newest first.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedOct 28, 2026

addedInput schema / properties / limit / description
```
Added value: +"How many files at most."
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": {},
+  "properties": {
+    "items": {
+      "description": "The files, newest first.",
+      "items": {
+        "additionalProperties": {},
+        "properties": {
+          "id": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "kind": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "name": {
+            "type": [
+              "string",
+              "null"
+            ]
+          },
+          "status": {
+            "type": [
+              "string",
+              "null"
+            ]
+          }
+        },
+        "type": "object"
+      },
+      "type": "array"
+    }
+  },
+  "type": "object"
+}

First observedOct 26, 2026

TDQS

A3.7/5.0

Behavior4/5

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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description adds real behavior beyond them: newest-first ordering, the three status values with error text on failure, and the caveat that a video has no thumbnail yet. It does not say what happens past the limit cap, but the added context is substantial.

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

Conciseness4/5

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

Front-loaded with the resource and ordering, then the field inventory, then the actionable 'Use the ids as mediaIds' instruction. The field enumeration is dense but each item carries information an agent may need; nothing is filler, though the list could be tightened.

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?

For a simple two-parameter read tool with an output schema and full annotation coverage, this is close to sufficient: ordering, status semantics, and downstream id usage are all stated. The only gap is pagination behavior beyond the 200-item cap, which the description never addresses.

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?

Schema description coverage is 100%, so both parameters are already documented, and the description only echoes the status values without adding syntax or format detail. The 'limit' parameter is not mentioned at all in the description, so it neither helps nor hurts.

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?

The description names a specific resource (images and videos in the media library) and its ordering (newest first), so an agent can tell it apart from postfjord_get_media. It never explicitly states the verb 'list' or names the sibling it replaces, but the scope is unambiguous.

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

Usage Guidelines3/5

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

There is a useful downstream hint ('Use the ids as mediaIds') that tells the agent why to call this before another tool, but no explicit when-to-use versus when-not-to-use guidance, and no mention of postfjord_get_media as the single-item alternative.

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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