Get Mailbox Profile

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds the useful framing that it reads the credential's current mailbox scope, but it says nothing about the ETag/304 conditional-request behavior implied by the If-None-Match parameter, which is the main non-obvious trait of this call.

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?

Two short sentences, front-loaded with the use case before the return claim, with no filler. Slight redundancy between "identify the authenticated mailbox" and "profile details for the mailbox key in use," which keeps it off a 5.

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 trivial two-optional-parameter read with rich annotations and an output schema, the description covers the essentials and need not describe return values. However, in this sibling set the primary risk is picking the wrong identity/session/connection tool, and the definition does nothing to mitigate that.

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 coverage is 100%, so both parameters (mailbox_id and If-None-Match) are fully documented in structured data. The description's phrase "mailbox key currently in use" lightly reinforces the default-mailbox behavior but adds no syntax, format, or selection guidance beyond the schema. 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 says it returns "profile details for the mailbox key currently in use," which is a specific resource and verb, but it does not differentiate from near-identical siblings like mailbox_get_identity, mailbox_get_session, mailbox_get_connection, and mailbox_list_granted_mailboxes. An agent facing that crowded namespace cannot tell from this text which one answers "who am I / which mailbox is this."

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?

"Use this to identify the authenticated mailbox before acting on mail" gives an implied usage context and ordering, but states no exclusions and never names an alternative. With four plus peers that also expose mailbox/identity context, the missing when-not guidance is a real gap.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.