mark_emails_readMark messages as read.
| Name | Required | Description | Default |
|---|---|---|---|
| accountId | No | Account to operate on. Optional when exactly one account is connected. | |
| messageIds | Yes | Messages to change, up to 100 IDs |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "additionalProperties": false,
+ "properties": {
+ "data": {
+ "additionalProperties": true,
+ "properties": {
+ "action": {
+ "type": "string"
+ },
+ "failed": {
+ "items": {
+ "additionalProperties": false,
+ "properties": {
+ "code": {
+ "type": "string"
+ },
+ "messageId": {
+ "type": "string"
+ }
+ },
+ "required": [
+ "messageId",
+ "code"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "succeededIds": {
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ },
+ "uncertainIds": {
+ "items": {
+ "type": "string"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "action",
+ "succeededIds",
+ "failed",
+ "uncertainIds"
+ ],
+ "type": "object"
+ }
+ },
+ "required": [
+ "data"
+ ],
+ "type": "object"
+}Input schema / properties / accountId / anyOfPrevious value: -[
- {
- "minLength": 1,
- "type": "string"
- },
- {
- "type": "null"
- }
-]New value: +[
+ {
+ "maxLength": 512,
+ "minLength": 1,
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+]Input schema / properties / messageIds / descriptionPrevious value: -"Messages to change, up to 100 distinct IDs"New value: +"Messages to change, up to 100 IDs"Input schema / properties / messageIds / items / maxLengthAdded value: +512Input schema / properties / messageIds / maxItemsAdded value: +100Input schema / $schemaPrevious value: -"https://json-schema.org/draft/2020-12/schema"New value: +"http://json-schema.org/draft-07/schema#"Input schema / properties / accountId / anyOfAdded value: +[
+ {
+ "minLength": 1,
+ "type": "string"
+ },
+ {
+ "type": "null"
+ }
+]Input schema / properties / accountId / descriptionAdded value: +"Account to operate on. Optional when exactly one account is connected."Input schema / properties / accountId / maxLengthRemoved value: -512Input schema / properties / accountId / minLengthRemoved value: -1Input schema / properties / accountId / typeRemoved value: -"string"Input schema / properties / messageIds / descriptionAdded value: +"Messages to change, up to 100 distinct IDs"Input schema / properties / messageIds / items / maxLengthRemoved value: -512Input schema / properties / messageIds / maxItemsRemoved value: -100Input schema / $schemaPrevious value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered structurally. The description adds nothing beyond that — no mention that the operation is a bulk state change, that unread flags are cleared irreversibly from the server's view, or what the output contains.
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?
It is a single front-loaded sentence with no waste, but that is because it carries almost no information. Brevity here reflects under-specification rather than disciplined editing.
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 and full parameter documentation exist, so return values and params need not be explained. However, for a batch mutation tool, the description supplies no behavioral context an agent needs — no note on idempotency semantics, account defaulting, or the sibling unread counterpart.
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 accountId and messageIds (including the 100-ID cap) are fully documented in the schema. The description's word 'messages' hints at messageIds but adds no syntax, batching, or account-resolution detail beyond the schema.
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?
The sentence 'Mark messages as read' simply restates the tool name and title with no additional specificity. It does not distinguish this from the sibling mark_emails_unread, nor clarify scope (which messages, which folders, per-account behavior).
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 versus alternatives is provided. The obvious alternative, mark_emails_unread, exists as a sibling and is never mentioned, nor is there any exclusion or precondition stated.
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.