Terminates a JAR session and removes temporary files to reclaim disk space and prevent leftover data.
Close a JAR session and clean up temp files.
| Name | Required | Description | Default |
|---|---|---|---|
| cleanup | No | Delete temp files (default: true) | |
| session_id | Yes | Session ID |
Changes observed during successful MCP inspections.
v0.1.4Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does disclose the core effect (session termination plus temp-file cleanup), which is more than the name alone, but omits whether the session is invalidated, whether repeated closes fail, and that cleanup is destructive.
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?
A single front-loaded sentence with no filler; the primary action and its side effect are stated immediately.
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 two-parameter, no-output-schema tool the essentials are present, but with zero annotation coverage the description should note session invalidation and the destructive nature of cleanup to fully equip an agent.
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%, so both parameters (session_id, cleanup) are already documented in the schema. The description adds no semantics about session_id validity or the cleanup default/override behavior beyond what the schema states.
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 (close) and resource (JAR session) plus the side effect of cleaning up temp files. The inverse relationship to jar_open makes it distinguishable without opening the schema, though it never names that sibling explicitly.
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?
Usage is only implied (close a session when finished). No statement of when to call it, prerequisites, or relationship to jar_open/jar_list_sessions, and no guidance on whether the cleanup path is optional in practice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.