opencode_session_create

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

With no annotations, the description carries the full behavioral burden, yet it says nothing about persistence, whether parentID must reference an existing session, permission requirements, or what the call returns. "Create" implies mutation but no side effects or lifecycle details are disclosed.

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?

Two short sentences, front-loaded with the action and followed by the optional inputs. It is efficient, though the brevity edges toward under-specification rather than deliberate conciseness.

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?

There is no output schema and no annotations, so the description should explain what a caller gets back (a session identifier for subsequent opencode_message_send or opencode_session_get calls) and whether parentID affects session behavior. Neither is covered, leaving the definition thin for a creation tool.

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 description coverage is 100%, so the schema already documents all three parameters including the directory field the description omits. The mention of parentID and title adds no syntax or constraint information beyond what the schema states, so baseline 3 applies.

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 and resource ("Create a new session") so the operation is immediately identifiable. It does not distinguish itself from sibling creators such as opencode_session_fork, which also produces a session, so it stops short of 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 gives no when-to-use context and never names the alternative (opencode_session_fork) for deriving a session from an existing one. The only guidance is the word "Optionally" attached to parentID and title.

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