invariance_kb_session_list_messages

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

Annotations declare readOnlyHint=true and openWorldHint=true, which already inform the agent that this is a safe read operation. The description adds minimal extra behavioral context: it mentions messages appear 'in order,' but doesn't clarify what 'order' means (e.g., chronological by timestamp) or the exact response structure. With annotations covering the safety profile, a 3 is fair as the description adds some value but not rich behavioral detail.

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 a single concise sentence that clearly states the action and resource. It is front-loaded and economical; every word earns its place. No fluff or unnecessary detail.

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 operation with one parameter and no output schema, the description is quite complete. It states what it does and the order of messages. It could benefit from mentioning the order basis (e.g., chronological) and any pagination details, but these are not critical for basic usage. Given the simplicity, a 4 is appropriate.

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?

The schema has 1 parameter 'id' with no description (0% coverage). The description does not explain 'id' beyond its apparent role as session identifier. Since the tool name includes 'session' and description mentions 'session,' an agent can infer 'id' is the session ID, but the description adds minimal meaning beyond the schema. Baseline is 3 given high parameter simplicity, but low schema coverage means description should compensate; it partially does.

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 clear purpose: 'List all messages in a KB ask session in order.' It specifies the resource (KB ask session) and the operation (list messages). It distinguishes from sibling tools like invariance_kb_session_create and invariance_kb_session_append_message by implying a read operation on existing sessions, but it doesn't explicitly name a sibling to differentiate from, so not 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?

The description implies when to use this tool: when you need to view messages in a sessionrowth. It doesn't provide explicit guidance on when not to use it or alternatives, but the context of listing messages is clear given the sibling set includes create/append/delete session tools. A 3 is appropriate because there is implied guidance but no explicit exclusions.

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