fmsg-mcp

Check fmsg delivery

delivery_status

Read-onlyIdempotent

Track per-recipient delivery state for an fmsg message by ID, including recipients added later, with delivered times, response codes, pending deliveries, and retries.

Instructions

Per-recipient delivery state of a message, including recipients added later. For a message you sent it is the delivery to each recipient; for a received message your host knows only its own receipt. Each entry has the delivered time and, when recorded, the receiving host's fmsg response code (200 accepted; others, such as 100 user unknown, are rejections). Delivery is asynchronous: pending recipients may still be delivered, and temporary failures are retried.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`id`	Yes	fmsg message id

Output Schema

TableJSON Schema

Name	Required	Description	Default
`id`	Yes
`sent_at`	Yes
`recipients`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed10 schema fields changedv1.1.0Oct 15, 2026

addedInput schema / additionalProperties
```
Added value: +false
```
changedOutput schema / additionalProperties
```
Previous value: -falseNew value: +{}
```
changedOutput schema / properties / recipients / items / additionalProperties
```
Previous value: -falseNew value: +{}
```

addedOutput schema / properties / recipients / 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 / recipients / items / properties / code_meaning

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

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

addedOutput schema / properties / recipients / 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 / recipients / items / properties / via / enum
```
Removed value: -[
-  "to",
-  "add_to"
-]
```

First observedv0.1.3Sep 5, 2026

TDQS

A4.1/5.0

Behavior5/5

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

Beyond the readOnly/idempotent annotations, the description discloses materially useful behavior: delivery is asynchronous, pending recipients may still be delivered, temporary failures are retried, and it decodes response codes (200 accepted, 100 user unknown as rejection). This is exactly the context an agent needs to interpret results correctly.

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?

The purpose is front-loaded and every subsequent sentence adds value (scenario semantics, response-code meaning, async caveat). It is dense but no sentence is filler.

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?

With an output schema present the description needn't enumerate return values, and it already explains entry contents (delivered time, response code). It is essentially complete, missing only explicit alternative-routing guidance.

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% and the single id parameter is documented as 'fmsg message id', so the schema carries the load. The description adds no syntax or format detail beyond that, so baseline 3 applies.

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?

The description states a specific verb and resource - the per-recipient delivery state of a message - and explicitly scopes it apart from content-retrieval siblings like get_message. An agent can immediately tell this tool is about delivery outcomes, not message bodies.

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?

It frames the two relevant scenarios (a message you sent vs a received message), which implies when the tool applies, but it never names an alternative or a when-not condition. The guidance is implied rather than explicit.

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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