session_list

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

With no annotations provided, the description carries the burden. It discloses the ordering behavior and the exact return fields, which goes beyond just the tool name. It does not mention side effects, but 'List' implies a read-only operation, and the return format is specified.

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 highly concise: two sentences that state the purpose, ordering, and return format. No unnecessary words or redundant information exist.

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, parameterless list tool, the description provides sufficient detail: it names the resource, the return fields, and the ordering. The existence of an output schema (not shown) reduces the need to explain return values further. However, it lacks context on when to use it relative to sibling tools, which is a minor gap.

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 tool has zero parameters, so there are no parameter semantics to clarify. Per the rubric, a baseline of 4 is appropriate because the description correctly notes the return structure, which is the only relevant semantic here.

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 action ('List') and the resource ('all persisted sessions'), including ordering ('most recently updated first'). This distinguishes it from sibling tools like session_status or session_get_steps, which operate on individual sessions.

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 usage: if you need a list of all persisted sessions, use this tool. However, it does not explicitly mention when not to use it or suggest alternatives for session-specific operations, so guidance is implied rather than explicit.

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