Read one school email by its Mailbox:id reference, returning subject, sender, date, and body. Fetch a single inbox message without marking it read.
Read one School email by ref 'Mailbox:id' (subject, from, date, body).
| Name | Required | Description | Default |
|---|---|---|---|
| ref | Yes | ||
| max_body | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does not disclose whether reading an email marks it as read, what permissions/auth are required, how invalid refs are handled, or any rate limits — a real gap for a mailbox read that may mutate read-state.
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 front-loaded sentence: verb, resource, identifier format, and return fields. No wasted text.
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 exists, so enumerating return fields was optional, and the read/mutation behavior and max_body semantics are the main omissions. Adequate but leaves meaningful gaps for a no-annotation tool.
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 compensate. It usefully defines the ref format ('Mailbox:id'), which the bare schema 'Ref' does not, but completely omits max_body (default 4000) and its truncation behavior.
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?
Specific verb+resource ('Read one School email') with the exact ref format 'Mailbox:id' and the returned fields named. It implicitly separates itself from schoolmail_search (many) by emphasizing 'one', though it never explicitly names a sibling.
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 phrase 'by ref Mailbox:id' implies you must already hold a ref (e.g. from schoolmail_search or schoolmail_folders), which is usable context. But there is no explicit when-to-use/when-not statement or named alternative.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.