mark_emails_readMarks up to 100 specified email messages as read in a connected Gmail, Outlook, or IMAP account, with an optional account ID when multiple accounts are available.
Mark 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.
v0.19.0Input 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: +100v0.16.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so the safety profile is fully covered; the description adds nothing new such as whether marking read is reversible or what happens to messages not owned by the account. With an output schema present and annotations complete, the description contributes no incremental behavioral context.
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?
One short sentence with no padding, but also no structure or front-loaded scoping information beyond the verb. Brevity here reflects under-specification rather than efficiency.
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?
The tool mutates state, but the description never says what changes, whether the operation is batch-limited, or how it differs from the unread counterpart. Annotations and the output schema carry most of the weight, leaving the description far short of what a mutation tool should explain.
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%: accountId's optional-when-single-account behavior and the 1-100 messageIds limit are already documented in the schema. The description adds no parameter meaning, 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?
The description 'Mark messages as read' restates the tool name and title almost verbatim, adding no scope, verb nuance, or resource detail. It does not distinguish the tool from the sibling mark_emails_unread, so an agent gains nothing beyond what the name already says.
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 is given on when to use this versus alternatives such as mark_emails_unread or archive_emails. There is not even an implied workflow hint (e.g., after reading a message body).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.