Mark a message as read or unread by setting or clearing its \Seen flag for a given account, folder, and UID.
Mark a message as read or unread by setting or clearing its \Seen flag.
Args: account: Account name from list_accounts. folder: Folder containing the message. uid: Message UID. read: True to mark read (default), false to mark unread.
| Name | Required | Description | Default |
|---|---|---|---|
| uid | Yes | ||
| read | No | ||
| folder | Yes | ||
| account | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does 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. The description adds genuine context by explaining the set/clear Seen-flag mechanism, which is why the operation is idempotent, but it says nothing about permission requirements, error behavior for a missing UID, or server-side effects.
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?
The purpose is front-loaded in one sentence and the argument list is tight with no filler. The Args block is slightly redundant with the schema but earns its place given zero schema description coverage.
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?
For a simple idempotent toggle with annotations covering the safety profile and no output schema, the description supplies everything needed to invoke it correctly: all four parameters, the default, and the resulting state change. Only return/error behavior is left implicit.
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 0%, so the description must carry the full burden and largely does: it documents account (and its source, list_accounts), folder, uid, and the read flag with its default and inverted semantics. Only 'uid: Message UID' is tautological.
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 ('Mark a message as read or unread') and even names the underlying mechanism (the \Seen flag), so the effect is unambiguous. It does not, however, distinguish itself from the sibling 'flag_message', which an agent could plausibly confuse with this toggle.
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 never says when to use this tool versus 'flag_message' or when reading a message ('read_email') would be the alternative. The only routing hint is the parenthetical that 'account' comes from list_accounts, which is parameter provenance rather than usage guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.