Bus Inbox

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

No annotations are present, so the description carries the burden of behavioral disclosure. It explains the default message scope (workspace-addressed plus broadcasts) and the exclusion of other sessions, which is meaningful behavior beyond the parameter names. It does not disclose ordering or whether listing mutates read state, but for a read-only list these are minor gaps.

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?

Two short paragraphs with the core purpose front-loaded in the first sentence. The follow-up clarifies defaults and the one conditional flag without wasted words.

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 simple list tool with two optional boolean parameters and an output schema, the description covers the key context an agent needs: what is listed, what is excluded by default, and when to set all_sessions. The unread_only option is sufficiently documented in the schema.

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 parameters are already documented. The description reinforces the all_sessions behavior by stating that other sessions' queues are left out by default, but it adds little beyond the schema's own parameter descriptions.

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?

Opens with a specific verb and resource: 'List pending messages for this session,' which clearly distinguishes the inbox-listing behavior from the sibling tools (bus_read, bus_send, bus_status). The scope is explicit ('for this session'), and the default inclusion rules are stated.

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 gives clear context on when the defaults apply and when to set all_sessions: 'Other sessions' queues are left out unless all_sessions is set.' It does not explicitly name sibling alternatives or say when to prefer bus_read/bus_status, but the listing-versus-reading intent is implied.

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