session_continue

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

With no annotations provided, the description carries the burden of explaining behavior. It discloses the key trait of auto-selecting the latest session when thread_id is omitted, and describes the take-over-and-continue behavior. It lacks details on side effects or error handling, but for a continuation tool, this is reasonably transparent.

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 succinct and well-structured: a one-line purpose, a follow-up behavioral note, and a clearly formatted Args list. Every sentence adds value, with no filler or redundancy.

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 presence of an output schema (return values are covered) and 5 parameters with full descriptions, the description is complete. It covers the purpose, key behavior, and all parameter semantics, making it self-sufficient for an agent to use the tool correctly.

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 0%, so the description fully compensates by listing and explaining all five parameters in the Args block (prompt, thread_id, model, sandbox, timeout). Each parameter gets a concise but meaningful description, adding semantics beyond the schema's type/default information.

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 tool's purpose: '前回のCodexセッション（スレッド）を引き継いで継続実行' (continue by taking over the previous Codex session/thread). This specific verb+resource combination distinguishes it from siblings like session_list (listing) and execute (starting new).

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 clear context by explaining that omitting thread_id automatically takes over the latest session, which guides when to use the tool. However, it does not explicitly state when not to use it or name alternatives, though the sibling tools imply the contrast.

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