list_accounts_addAdd accounts to a Mastodon list by specifying the list ID and account IDs to organize followed accounts.
Add accounts to a list.
| Name | Required | Description | Default |
|---|---|---|---|
| list_id | Yes | Numeric list ID. | |
| account_ids | Yes | List of numeric account IDs to add. |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.0.5Input schema / additionalPropertiesAdded value: +falseOutput schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "result": {
+ "type": "string"
+ }
+ },
+ "required": [
+ "result"
+ ],
+ "type": "object",
+ "x-fastmcp-wrap-result": true
+}v1.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety and idempotency profile is covered. The description adds nothing beyond the basic action; it does not explain effects like duplicate handling (implied by idempotentHint) or response behavior, which would add value.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single sentence that is front-loaded and wastes no words. Perfectly concise for a simple tool.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the simple parameters, full schema coverage, annotations, and existing output schema, the description is adequate for correct invocation. It could mention idempotency or duplicate handling, but the annotations cover the essential behavioral traits.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so parameters are fully documented in the schema. The description adds no extra meaning beyond what the schema provides; baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb (add) and resources (accounts to a list), which is clear enough to distinguish from siblings like list_accounts_delete. However, it doesn't differentiate from list_accounts (the read counterpart) as explicitly as it could.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this instead of list_accounts_delete or how it relates to list_accounts. The tool is implied to be for modifying list membership, but no exclusions or alternatives are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.