get_user_by_idRead a public Synoptic profile by user ID. Use get_user for a username, or get_me for the signed-in account. Unknown IDs return User not found.
| Name | Required | Description | Default |
|---|---|---|---|
| userId | Yes | Synoptic user ID, such as a stream’s authorId or an id from get_followers |
| 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,
- "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"
+ }
+]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 / userId / descriptionAdded value: +"Synoptic user ID, such as a stream’s authorId or an id from get_followers"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 declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely new behavior: the profile is 'public' (implying private/restricted users may be invisible or partial) and unknown IDs return 'User not found' rather than an empty object. It stops short of saying whether a non-existent-but-valid-format ID differs from a malformed one.
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?
Three short sentences, zero filler. The positive capability comes first, then routing to alternatives, then the error case — well front-loaded for scanning.
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?
With an output schema present, return shape need not be described. For a single-parameter read tool with full annotation coverage, capability, sibling routing, and error behavior are all present; nothing an agent needs to invoke it correctly is missing.
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 userId parameter is fully documented there, including where IDs come from (stream authorId, get_followers). The description adds no syntax, format, or validation detail 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 ('Read a public Synoptic profile by user ID') and immediately scopes it against the two nearest siblings, get_user (by username) and get_me (signed-in account). An agent can distinguish this tool from every other get_* sibling without opening a 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?
Explicitly names the alternatives and the condition that selects each one: use get_user when you have a username, get_me for the signed-in account, otherwise this. It also states the failure condition for an unknown ID, which removes ambiguity about retrying.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.