set_usernameSet the signed-in user’s public Synoptic username to a saved suggestion or their verified X handle. Generate suggestions first when needed.
| Name | Required | Description | Default |
|---|---|---|---|
| username | Yes | One of the latest generate_username_suggestions results or the verified X handle (xComHandle in get_me), matched exactly; other values are rejected |
| Name | Required | Description | Default |
|---|---|---|---|
| user | Yes |
Changes observed during successful MCP inspections.
Output schema / properties / user / properties / avatar / anyOfPrevious value: -[
- {
- "additionalProperties": false,
- "properties": {
- "bucket": {
- "description": "S3 bucket holding the image",
- "minLength": 1,
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- "height": {
- "anyOf": [
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- "type": "integer"
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- "description": "Height in pixels"
- },
- "key": {
- "description": "Storage key of the image",
- "minLength": 1,
- "type": "string"
- },
- "region": {
- "description": "AWS region of the bucket",
- "minLength": 1,
- "type": "string"
- },
- "type": {
- "description": "MIME type, such as image/png",
- "minLength": 1,
- "type": "string"
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- "width": {
- "anyOf": [
- {
- "exclusiveMinimum": 0,
- "type": "integer"
- },
- {
- "type": "null"
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- ],
- "description": "Width in pixels"
- }
- },
- "required": [
- "bucket",
- "key",
- "region",
- "type"
- ],
- "type": "object"
- },
- {
- "type": "null"
- }
-]New value: +[
+ {
+ "additionalProperties": false,
+ "properties": {
+ "bucket": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "height": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ },
+ "key": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "region": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "type": {
+ "description": "MIME type, such as image/png",
+ "minLength": 1,
+ "type": "string"
+ },
+ "width": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ }
+ },
+ "required": [
+ "bucket",
+ "key",
+ "region",
+ "type"
+ ],
+ "type": "object"
+ },
+ {
+ "type": "null"
+ }
+]Output schema / properties / user / properties / backgroundImage / anyOfPrevious value: -[
- {
- "additionalProperties": false,
- "properties": {
- "bucket": {
- "description": "S3 bucket holding the image",
- "minLength": 1,
- "type": "string"
- },
- "height": {
- "anyOf": [
- {
- "exclusiveMinimum": 0,
- "type": "integer"
- },
- {
- "type": "null"
- }
- ],
- "description": "Height in pixels"
- },
- "key": {
- "description": "Storage key of the image",
- "minLength": 1,
- "type": "string"
- },
- "region": {
- "description": "AWS region of the bucket",
- "minLength": 1,
- "type": "string"
- },
- "type": {
- "description": "MIME type, such as image/png",
- "minLength": 1,
- "type": "string"
- },
- "width": {
- "anyOf": [
- {
- "exclusiveMinimum": 0,
- "type": "integer"
- },
- {
- "type": "null"
- }
- ],
- "description": "Width in pixels"
- }
- },
- "required": [
- "bucket",
- "key",
- "region",
- "type"
- ],
- "type": "object"
- },
- {
- "type": "null"
- }
-]New value: +[
+ {
+ "additionalProperties": false,
+ "properties": {
+ "bucket": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "height": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ },
+ "key": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "region": {
+ "minLength": 1,
+ "type": "string"
+ },
+ "type": {
+ "description": "MIME type, such as image/png",
+ "minLength": 1,
+ "type": "string"
+ },
+ "width": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ]
+ }
+ },
+ "required": [
+ "bucket",
+ "key",
+ "region",
+ "type"
+ ],
+ "type": "object"
+ },
+ {
+ "type": "null"
+ }
+]Input schema / properties / username / descriptionAdded value: +"One of the latest generate_username_suggestions results or the verified X handle (xComHandle in get_me), matched exactly; other values are rejected"Output schema / properties / user / properties / avatar / anyOfPrevious value: -[
- {
- "additionalProperties": false,
- "properties": {
- "bucket": {
- "minLength": 1,
- "type": "string"
- },
- "height": {
- "anyOf": [
- {
- "exclusiveMinimum": 0,
- "type": "integer"
- },
- {
- "type": "null"
- }
- ]
- },
- "key": {
- "minLength": 1,
- "type": "string"
- },
- "region": {
- "minLength": 1,
- "type": "string"
- },
- "type": {
- "minLength": 1,
- "type": "string"
- },
- "width": {
- "anyOf": [
- {
- "exclusiveMinimum": 0,
- "type": "integer"
- },
- {
- "type": "null"
- }
- ]
- }
- },
- "required": [
- "bucket",
- "key",
- "region",
- "type"
- ],
- "type": "object"
- },
- {
- "type": "null"
- }
-]New value: +[
+ {
+ "additionalProperties": false,
+ "properties": {
+ "bucket": {
+ "description": "S3 bucket holding the image",
+ "minLength": 1,
+ "type": "string"
+ },
+ "height": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "description": "Height in pixels"
+ },
+ "key": {
+ "description": "Storage key of the image",
+ "minLength": 1,
+ "type": "string"
+ },
+ "region": {
+ "description": "AWS region of the bucket",
+ "minLength": 1,
+ "type": "string"
+ },
+ "type": {
+ "description": "MIME type, such as image/png",
+ "minLength": 1,
+ "type": "string"
+ },
+ "width": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "description": "Width in pixels"
+ }
+ },
+ "required": [
+ "bucket",
+ "key",
+ "region",
+ "type"
+ ],
+ "type": "object"
+ },
+ {
+ "type": "null"
+ }
+]Output schema / properties / user / properties / avatar / descriptionAdded value: +"Profile image; null when none is set"Output schema / properties / user / properties / backgroundImage / anyOfPrevious value: -[
- {
- "$ref": "#/properties/user/properties/avatar/anyOf/0"
- },
- {
- "type": "null"
- }
-]New value: +[
+ {
+ "additionalProperties": false,
+ "properties": {
+ "bucket": {
+ "description": "S3 bucket holding the image",
+ "minLength": 1,
+ "type": "string"
+ },
+ "height": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "description": "Height in pixels"
+ },
+ "key": {
+ "description": "Storage key of the image",
+ "minLength": 1,
+ "type": "string"
+ },
+ "region": {
+ "description": "AWS region of the bucket",
+ "minLength": 1,
+ "type": "string"
+ },
+ "type": {
+ "description": "MIME type, such as image/png",
+ "minLength": 1,
+ "type": "string"
+ },
+ "width": {
+ "anyOf": [
+ {
+ "exclusiveMinimum": 0,
+ "type": "integer"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "description": "Width in pixels"
+ }
+ },
+ "required": [
+ "bucket",
+ "key",
+ "region",
+ "type"
+ ],
+ "type": "object"
+ },
+ {
+ "type": "null"
+ }
+]Output schema / properties / user / properties / backgroundImage / descriptionAdded value: +"Profile background image; null when none is set"Output schema / properties / user / properties / followersCount / descriptionAdded value: +"Users following this user"Output schema / properties / user / properties / followingCount / descriptionAdded value: +"Users this user follows; excludes streams"Output schema / properties / user / properties / id / descriptionAdded value: +"Synoptic user ID for follow_user, is_following_user or get_user_by_id"Output schema / properties / user / properties / isHighlighted / descriptionAdded value: +"Featured by Synoptic; listed by get_highlighted_authors"Output schema / properties / user / properties / xComHandle / descriptionAdded value: +"Verified X handle linked to this profile, without @"Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already disclose destructiveHint=true, idempotentHint=true, and openWorldHint=true, lowering the bar. The description adds that the username is public and that values outside the two accepted sources are rejected, but it does not explain what is destroyed or replaced by the previous username, so it adds only modest context beyond the annotations.
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?
Two short sentences, action statement first and the prerequisite second, with no filler. Every clause carries information.
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?
An output schema exists so return values need not be explained, and the description covers the value constraint and the prerequisite tool. It is close to complete, though for a destructive, open-world write it could note permanence or rate-limit considerations.
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% and the single parameter is already documented as 'one of the latest generate_username_suggestions results or the verified X handle'. The description restates that constraint but adds no new syntax, format, or matching rules beyond the schema, so the baseline 3 applies.
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 and resource ('Set the signed-in user's public Synoptic username') and constrains the source of the value to a saved suggestion or verified X handle. An agent can distinguish this from the sibling generate_username_suggestions without opening the schema.
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?
The description explicitly routes the workflow by telling the agent to run generate_username_suggestions first when needed, and it names the two acceptable value sources. It does not spell out when-not-to-use cases or what happens if the username is already set, so it stops short of a full 5.
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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