opencode_end_session

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

With no annotations provided, the description carries the burden of behavioral disclosure. It discloses that the tool closes a session and frees resources, which implies a state change. However, it does not explain whether the session's history is preserved, whether the action is reversible, or what side effects occur beyond resource freeing.

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 consists of two concise sentences, both front-loaded with essential information. Every word adds value, and there is no unnecessary repetition or fluff.

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 tool with one parameter and an output schema, the description is largely complete. It defines the action, when to use it, and the resource affected. A minor gap is the lack of information about session lifecycle after closing (e.g., can it be reopened, does history remain), but this is not critical for a basic close operation.

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 provides a clear description for the single parameter ('Session ID to close') with 100% coverage. The description adds no additional context about the parameter format or semantics, so it earns the baseline score for high schema coverage.

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 uses a specific verb 'Close' and names the resource 'opencode session', clearly distinguishing it from siblings like opencode_start_session and opencode_shutdown. It also indicates the action's outcome ('free its resources'), providing a complete purpose.

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 explicitly states when to use the tool ('Call this when a task is complete') and provides a caution ('Do not leave sessions open indefinitely'). However, it does not name alternative tools or explain when not to use it, such as distinguishing from opencode_shutdown.

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