jar_list_sessions

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

With no annotations, the description carries the full behavioral burden. It mentions 'active' sessions, which hints at filtering, but does not disclose whether the operation is read-only, whether it has side effects, what constitutes a session, or what the result format looks like. For a zero-annotation tool, this is a significant gap.

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, front-loaded sentence that wastes no words. It is appropriately sized for a simple list operation, though it could benefit from one additional clarifying clause without becoming verbose.

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?

Given the tool's simplicity (0 params, no output schema), the description is minimally adequate but leaves key context unstated. It does not explain what a 'session' is in this context, nor does it describe the return value, which is important since no output schema exists. An agent can guess, but the definition could be more helpful.

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 accepts no parameters, so the schema provides no parameter details to supplement. Per the rubric, a zero-parameter tool receives a baseline of 4 for parameter semantics. The description adds no parameter-related information, which is appropriate 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 states a specific verb ('List') and resource ('active JAR sessions'), making the tool's function clear. However, it does not explicitly differentiate from siblings like jar_open, jar_close, or jar_list, leaving the agent to infer that 'sessions' refers to currently open JAR files rather than, say, files inside a JAR.

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 no guidance on when to use this tool versus alternatives. There is no mention of prerequisites (e.g., needing an open session), exclusions, or when to prefer jar_open or jar_close. An agent receives only a bare statement of effect.

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