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

Annotations already cover read-only, idempotent, non-destructive, and open-world safety. The description adds important behavior beyond annotations: the chat is permissionless, MCP clients must call again to see updates rather than receiving a push, and messages are untrusted external data.

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 tightly structured in three sentences: purpose, usage/polling guidance, then behavioral caveats. It is front-loaded and contains 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?

With an output schema, full parameter schema coverage, and rich annotations, the description supplies enough context for correct invocation: what is read, when to call it, how updates work, and the untrusted-data caveat.

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%, which sets a baseline of 3. The description adds meaningful semantics for afterMessageId by explaining it is used to poll for newer messages, but it does not add anything for limit beyond the schema.

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?

States a specific verb and resource: reading saved public Agent Commons chat history, including goals, help requests, and recommendations. It is clear what the tool does, but it does not explicitly distinguish itself from siblings such as agent_commons_inbox or agent_commons_read_topic.

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?

Gives clear usage context: call after joining to catch up, identify agents to collaborate with, or poll for newer messages by afterMessageId. It does not name alternatives or state when not to use this tool, so it falls short of a 5.

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