Mailbox MCP

Create a folder

create_folder

Idempotent

Create an IMAP folder. The server's own namespace and hierarchy rules are applied, so it lands where the user would expect it in Outlook or webmail, and a folder created this way is SUBSCRIBED, so it shows up in clients that list only subscribed folders (Outlook and Roundcube both do). A "/" IN THE NAME BUILDS A HIERARCHY rather than a folder with a slash in its name: "Archive/2026" puts 2026 inside Archive, creating Archive too if it is missing - so a folder name cannot contain a literal "/". Safe to call twice: a folder of that name that already exists is returned as it is, matched case-insensitively, so asking for "projects" where "Projects" exists finds that one rather than leaving two folders nobody can tell apart - the reply says whether it actually created anything. parent may be a folder that cannot itself hold messages (selectable: false in list_mailboxes), because creating underneath one is what turns it into a real folder. REFUSES a name with a blank or empty segment, such as a leading, trailing or doubled "/".

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes	Folder name, e.g. "Invoices". A "/" nests: "Archive/2026" creates 2026 inside Archive.
`parent`	No	An existing folder to nest it under, e.g. "Archive". Use this rather than building the path by hand when the parent is already there.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

Changed2 schema fields changedSep 5, 2026

changedInput schema / properties / name / description

Previous value: -"Folder name, e.g. \"Invoices\"."New value: +"Folder name, e.g. \"Invoices\". A \"/\" nests: \"Archive/2026\" creates 2026 inside Archive."

changedInput schema / properties / parent / description

Previous value: -"Parent folder path to nest it under."New value: +"An existing folder to nest it under, e.g. \"Archive\". Use this rather than building the path by hand when the parent is already there."

First observedSep 5, 2026

TDQS

A5/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare idempotentHint=true, and the description goes well beyond that by explaining the case-insensitive matching behavior, the reply indicating whether anything was created, and the side effect of creating intermediate folders. It also discloses the subscription side effect, which is not visible in the annotations or schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is dense but every sentence adds critical behavior: namespace rules, hierarchy creation, idempotency, parent semantics, and refusal conditions. The most important fact (what '/' does) is explicitly highlighted, and the structure flows from common usage to edge cases without wasting words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a creation tool with two required/optional string parameters and no output schema, the description covers all likely unknowns: naming, nesting, idempotency, case sensitivity, subscription, parent limitations, and refusal conditions. Nothing needed to call the tool safely and correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3, but the description adds meaningful detail beyond the schema: it clarifies that '/' builds hierarchy, that 'parent' can be non-selectable, and that duplicate names are matched case-insensitively. This transforms the parameters from simple strings into well-understood behaviors.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description identifies the exact action and resource—'Create an IMAP folder'—and immediately distinguishes this operation from siblings like rename_folder and delete_folder by explaining server-side namespace behavior, subscription, and hierarchy creation. It is specific about what the tool does and what it does not do (e.g., no literal '/' in names).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit guidance on when to use `parent` versus building the path manually, explains that creating under a non-selectable parent is intentional and useful, and notes that it is safe to call twice, which conflicts with typical assumptions about creation tools. It also states when the tool refuses input, giving clear usage boundaries.

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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TDQS

A4.3/5.0

Disambiguation4/5

Most tools target clearly distinct actions and resource types, and the near-overlapping pairs (archive_email vs move_email, check_bounces vs check_receipts) are explicitly cross-referenced in their descriptions. However, the delivery-status pair genuinely overlaps — both scan inbound mail to answer "did my message get there?" — and archive_email is functionally a role-aware move_email, so an agent could still select the wrong one without careful reading.

Naming Consistency4/5

Virtually every tool follows a consistent verb_noun pattern with clear prefix families (check_*, create_*, draft_*, list_*, mark_*, read_*). The single outlier is not_junk, which breaks the mark_* symmetry of its counterpart mark_junk and is not a standard verb-noun construction, though it remains perfectly readable.

Tool Count3/5

31 tools is firmly in the heavy range, though email is a genuinely broad domain spanning send/reply/forward, three draft variants, folder management, flags, junk handling, and diagnostics. Real consolidation was possible — check_bounces and check_receipts could be one delivery-status tool, archive_email is a special case of move_email, and the read-state/flag pairs could take boolean parameters — but each tool has a defensible job.

Completeness4/5

The core email lifecycle is thoroughly covered: send/reply/forward, three draft types plus draft editing, read/search/list/thread, full folder CRUD, move/archive/delete, flags, read state, junk handling, and file-upload intake. Minor gaps exist — there is no permanent-deletion or purge tool, no filter/rules management, and identity/contact maintenance is deliberately out of scope — but real user workflows can be completed without dead ends.

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