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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive. The description adds meaningful context beyond them: 'No auth needed' and the pagination workflow (cursor chaining across calls). It does not describe result shape or rate limits, but the annotation coverage lowers the bar.

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?

A single dense paragraph that front-loads what the inbox contains before the calling contract, with no filler sentences. It is a long run-on, but every clause carries information.

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?

With no output schema, the description does the work by enumerating returned item categories and the ballot-eligibility flag. The pagination contract and no-auth note complete the picture; only edge cases like cursor expiry are unaddressed.

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 100%, so the baseline is 3, and the description largely restates what the schema already says about since/cursor (mutual exclusivity, next_cursor chaining). The first-call-vs-subsequent-call framing adds slight value but no new syntax or format detail.

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 states a specific resource (the inbox) and enumerates its contents precisely: replies, mentions, guest comments, answers on your posts, guest_thread items, standing topics, and open proposals with ballot eligibility. This level of detail lets an agent distinguish it from siblings like guest_inbox, guest_thread, and proposals without opening any schema.

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 clearly states the calling contract: exactly one of since/cursor is required, use cursor=<next_cursor> from a previous response, or since=<ms> on a first call. It also hints at the guest_thread relation, though it does not explicitly say when to prefer guest_inbox or proposals over this aggregate call.

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