XCut AI – Viral Content Research

Write caption

xcut_write_caption

Read-onlyIdempotent

Use this when the user wants a finished caption (hook, body, CTA and hashtags) for an Instagram, TikTok or YouTube Shorts post from a short concept. Free; no sign-in. Output is generic: for work based on the user's own posts, canvases or brand, use the signed-in XcutAI tools. Do not use for writing unrelated to social media or marketing content.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "platform": "<platform>",
      "concept": "<concept>"
    },
    "name": "xcut_write_caption"
  }
}

Input Schema

Name	Required	Description	Default
`tone`	No	Voice of the caption, e.g. "engaging", "funny", "calm".	engaging
`concept`	Yes	What the post shows or says, in a sentence or two.
`platform`	Yes	Where the caption will be posted.

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 9, 2026

TDQS

A4.5/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds value annotations cannot: the call is free, requires no sign-in, and its output is deliberately generic rather than brand-personalized — a meaningful expectation-setting detail. It stops short of describing output shape or any limits on repeated calls.

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?

Three sentences with no filler: the primary trigger comes first, then the free/no-sign-in qualifier, then the personalized-alternative routing and the exclusion. Every clause carries selection-relevant information.

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?

For a three-parameter, read-only generation tool with no output schema, the description covers trigger, platforms, delivered output components, cost, authentication state, output genericity, and the sibling to route to for personalized work. Nothing an agent needs to select or invoke it correctly is 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%: concept, platform (with enum) and tone (with default and examples) are all documented in the schema itself. The description adds no syntax, format or length guidance beyond that, so the baseline 3 is appropriate.

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 (write) and resource (caption) and enumerates the delivered parts — hook, body, CTA and hashtags — for three named platforms. It also distinguishes itself from the signed-in XcutAI tool family, so an agent can tell it apart from xcut_write_content 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 Guidelines5/5

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

Explicitly frames the trigger ('when the user wants a finished caption ... from a short concept'), names the alternative for personalized work ('for work based on the user's own posts, canvases or brand, use the signed-in XcutAI tools'), and adds an exclusion ('do not use for writing unrelated to social media or marketing content'). Use, alternative, and non-use cases are all covered.

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

All XCut AI – Viral Content Research tools Inspect

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