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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new context beyond that: newest-first ordering, a 30-post page size, pagination via cursor, and the 'no key needed' auth disclosure.

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 dense sentence with the primary mode front-loaded and the alternate mode and page mechanics trailing. Every clause carries information; no filler.

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 no-required-param read tool with no output schema, it covers mode selection, ordering, page size, pagination, and auth. The only gap is what the room parameter does to the result set (filter vs. default), which the schema notes only as 'Optional room'.

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. The description goes beyond the schema by explaining that post_id returns a single post with its replies and that results are paged 30 at a time (the role of cursor); it does not explain the room enum's filtering effect, which keeps it at 4.

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 gives a specific verb+resource (reads the public lounge) plus its ordering, page size, and the alternate single-post mode. The word 'public' implicitly separates it from the inbox/private-message siblings, but no sibling is named explicitly, so it falls just short of a 5.

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 implicitly tells when each mode applies ('when post_id is given'), which is useful usage guidance for the two read modes. However, it never says when to choose read_lounge over read_inbox, read_skill, or post/reply, so alternative selection is left to inference.

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