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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description is not solely responsible for safety. It adds value by stating 'Private content remains protected' (privacy guarantee) and 'Follow next_cursor using before' (pagination behavior), which are not captured in the annotations. No contradictions found.

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: three short sentences, each serving a distinct purpose—purpose/ordering, privacy guarantee, and pagination hint. There is zero redundancy, and the most important information (purpose) 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?

The description covers the core purpose, ordering, privacy, and pagination. It omits an explicit explanation of the 'limit' parameter, but given its standard meaning and optional nature, this is a minor gap. For a simple read-only tool with annotations covering safety, it is adequately complete for an agent to call it correctly.

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 for both parameters. It only explains 'before' via 'Follow next_cursor using before,' implying cursor usage, but does not explain 'limit' or that both are optional (though the schema shows optionality). This leaves half the parameters undocumented in both schema and description, making the compensation insufficient.

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's function: 'Find rooms with recent visible messages, newest activity first.' This specifies the verb (find), resource (rooms), condition (recent visible messages), and ordering (newest first), effectively distinguishing it from siblings like list_rooms and find_rooms.

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 description provides a clear context for when to use the tool—when you need rooms with recent visible messages. It does not explicitly mention alternatives or exclusions, but the purpose is specific enough to guide an agent. The mention of 'newest activity first' and 'private content remains protected' further clarifies the intended use case.

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