Skip to main content
Glama
conorbronsdon

Substack MCP Server

by conorbronsdon
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Remote

list_scheduled_posts

Read-only

Retrieve scheduled Substack posts in chronological order, showing title, audience, and publish time for read-only planning.

Instructions

List posts scheduled for future publication, soonest first. Read-only visibility into what's queued — scheduling itself is done in Substack's editor (this server does not schedule, publish, or delete long-form posts). Returns id, title, audience, and scheduled time (trigger_at).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
limitNoMax posts to return (1-50; Substack rejects anything higher, so larger values are clamped)
offsetNoNumber of posts to skip

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed6 schema fields changed
    • addedInput schema / properties / limit / exclusiveMinimum
      Added value: +0
    • addedInput schema / properties / limit / maximum
      Added value: +9007199254740991
    • changedInput schema / properties / limit / type
      Previous value: -"number"New value: +"integer"
    • addedInput schema / properties / offset / maximum
      Added value: +9007199254740941
    • addedInput schema / properties / offset / minimum
      Added value: +0
    • changedInput schema / properties / offset / type
      Previous value: -"number"New value: +"integer"
  2. Changed1 schema field changedv0.6.2
    • changedInput schema / properties / limit / description
      Previous value: -"Max posts to return (1-100)"New value: +"Max posts to return (1-50; Substack rejects anything higher, so larger values are clamped)"
  3. Addedv0.5.0

TDQS

A4.7/5.0
Behavior5/5

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

The readOnlyHint annotation is true and the description reinforces it by stating the tool does not schedule, publish, or delete posts. This fully discloses the tool's side effects (none).

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?

The description is concise and front-loaded with purpose and read-only nature. It avoids fluff and clearly states the return fields, making every sentence valuable.

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?

Even without an output schema, the description lists what is returned (id, title, audience, scheduled time). Combined with the read-only note and parameter descriptions, an agent has enough context to invoke the tool correctly.

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?

The schema provides complete descriptions for both parameters (limit and offset), so the baseline is 3. The description adds no extra parameter-specific information beyond the schema.

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?

Clearly states the verb 'List' and resource 'posts scheduled for publication', with the ordering 'soonest first'. The read-only note and reference to scheduling in the editor distinguish it from sibling tools like list_published_posts and list_drafts.

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

Usage Guidelines5/5

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

Explicitly says 'Read-only visibility into what's queued' and that scheduling itself is done in Substack's editor, clarifying when not to use this tool. It also mentions no publishing or deletion, providing clear boundaries.

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

Deploy Server

Other Tools