fmsg-mcp

List sent messages

list_sent

Read-onlyIdempotent

List messages sent from an address, newest first, including unsent drafts and per-recipient delivery states, to review outbound history and delivery progress.

Instructions

List messages sent by this address (including unsent drafts, shown with time null), newest first, with per-recipient delivery state. Use delivery_status for one message's detail.

Input Schema

Name	Required	Description
`limit`	No	page size (host maximum 100)
`offset`	No	number of newest messages to skip
`include_reactions`	No	also list reaction messages (normally hidden)

Output Schema

Name	Required	Description	Default
`count`	Yes
`offset`	Yes
`messages`	Yes
`next_offset`	Yes
`untrusted_content_notice`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed20 schema fields changedv1.1.0Oct 15, 2026

addedInput schema / additionalProperties
```
Added value: +false
```
changedOutput schema / additionalProperties
```
Previous value: -falseNew value: +{}
```
changedOutput schema / properties / messages / items / additionalProperties
```
Previous value: -falseNew value: +{}
```
addedOutput schema / properties / messages / items / properties / attachments / description
```
Added value: +"sorted by filename, the same order in every tool"
```
changedOutput schema / properties / messages / items / properties / attachments / items / additionalProperties
```
Previous value: -falseNew value: +{}
```

addedOutput schema / properties / messages / items / properties / attachments / items / properties / type

Added value: +{
+  "description": "media type; inferred from the filename when the host records none",
+  "type": "string"
+}

addedOutput schema / properties / messages / items / properties / compressed

Added value: +{
+  "description": "true when the body was sent deflate-compressed on the wire (see size)",
+  "type": "boolean"
+}

changedOutput schema / properties / messages / items / properties / delivery / items / additionalProperties
```
Previous value: -falseNew value: +{}
```

addedOutput schema / properties / messages / items / properties / delivery / items / properties / code / description

Added value: +"the receiving host's fmsg response code for the last attempt when recorded: 200 means accepted, other codes are rejections; null when not recorded, including some successful deliveries"

addedOutput schema / properties / messages / items / properties / delivery / items / properties / code_meaning

Added value: +{
+  "description": "the code's name in the fmsg specification, when known",
+  "type": [
+    "string",
+    "null"
+  ]
+}

addedOutput schema / properties / messages / items / properties / delivery / items / properties / status / description

Added value: +"one of \"delivered\", \"pending\", \"failed\"; delivered once the receiving host accepted it; failed when the last attempt was rejected (the host may retry temporary failures); otherwise pending. More values may be added"

removedOutput schema / properties / messages / items / properties / delivery / items / properties / status / enum
```
Removed value: -[
-  "delivered",
-  "pending",
-  "failed"
-]
```
addedOutput schema / properties / messages / items / properties / delivery / items / properties / time / description
```
Added value: +"when delivery was confirmed"
```

addedOutput schema / properties / messages / items / properties / delivery / items / properties / via / description

Added value: +"one of \"to\", \"add_to\"; how the recipient was addressed: to for the original recipients, add_to for recipients added later with the fmsg add-to mechanism (add_recipients). More values may be added"

removedOutput schema / properties / messages / items / properties / delivery / items / properties / via / enum
```
Removed value: -[
-  "to",
-  "add_to"
-]
```
addedOutput schema / properties / messages / items / properties / preview / description
```
Added value: +"start of the body; may be shorter than the full body"
```

addedOutput schema / properties / messages / items / properties / reaction

Added value: +{
+  "description": "the emoji when this message is itself a reaction (\"\" clears one); null otherwise",
+  "type": [
+    "string",
+    "null"
+  ]
+}

changedOutput schema / properties / messages / items / properties / reactions / items / additionalProperties
```
Previous value: -falseNew value: +{}
```

addedOutput schema / properties / messages / items / properties / size / description

Added value: +"body size in bytes as stored by your host: for a message you received with compressed true, the compressed wire length; your own sent messages store the uncompressed length. body_bytes, where given, is the decoded length"

addedOutput schema / properties / untrusted_content_notice
```
Added value: +{
+  "type": "string"
+}
```

First observedv0.1.3Sep 5, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds behavior beyond that: unsent drafts are included and identifiable by a null time, results are ordered newest first, and delivery state is attached per recipient — all of which affect how the agent interprets rows.

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 sentences, no filler; the key scope facts (sent-only, drafts included, ordering) lead, and the sibling routing comes last. Every clause carries information the agent needs.

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

Completeness5/5

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 not be spelled out, and the description still flags the two result quirks an agent would otherwise misread (draft rows with null time, per-recipient state). Pagination parameters are fully specified in the schema, leaving nothing material missing.

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 limit, offset and include_reactions are already documented. The description only reinforces ordering semantics ("newest first"), which contextualizes offset but adds no new parameter-level detail such as the host maximum of 100 or the reaction-hiding behavior.

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

Purpose5/5

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

States a specific verb and resource ("List messages sent by this address") plus the scope details that separate it from siblings: it covers unsent drafts and returns newest-first with per-recipient delivery state. An agent can distinguish it from list_messages without opening either schema.

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 routes the agent to delivery_status when it needs one message's detail, which is a genuine alternative-selection rule. It stops short of stating when to prefer list_messages over this tool or how to page through large result sets, so it is clear but not exhaustive.

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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