inbox

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

Annotations already declare readOnlyHint=true. The description adds value by detailing pagination behavior and the structure of return data (threads[], nextCursor, fields). No contradiction with annotations.

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 description is extremely concise: two sentences plus a filter list and an alternative tip. Every sentence adds value, and the most important information (purpose, pagination, key filters) is front-loaded.

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?

Given no output schema, the description compensates by specifying return structure and fields. It covers all major filters and provides a usage pointer to a sibling. Missing details like error handling or ordering, but still adequate for a read-only paginated list 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%, but the description explains the meaning of 6 out of 8 parameters (mailbox, campaign, label, read, includeNonreply, archived) including the enum options for archived and default for includeNonreply. Two parameters (limit, cursor) are only implicitly mentioned via pagination context, which is acceptable.

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 clearly states the tool returns a unified reply inbox across mailboxes, specifies cursor-paginated output with fields, and distinguishes from sibling 'thread' by telling to use that for one thread's history.

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?

It lists available filters and explicitly mentions an alternative tool ('Use thread for one thread's history'), providing clear context on when to use this tool. However, it does not explicitly state when not to use it.

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