Build Session Registry

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

No annotations are provided, so the description must cover behavioral traits. It discloses that the tool fails closed if stages still need an agent, and implies it does not do hidden work. It mentions immutability and expiring overlay, which are significant behavioral traits. However, it does not detail what failure returns or specific side effects beyond the fail-closed behavior, but the core transparency is present.

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 concise and front-loaded: the first line states the core purpose and key characteristics (immutable, expiring overlay). The second line provides crucial prerequisites and failure behavior. It is well-structured with no redundant information, every sentence earns its place.

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 complexity (finalizing a session overlay with guardrails) and the existence of an output schema, the description is fairly complete. It covers the main requirements (artifacts exist, fail-closed) and outcomes (immutable, expiring). It lacks details on parameter semantics and specific return behavior, but the presence of an output schema reduces the need for return documentation, and the essential context is present.

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%, and the description provides no parameter-specific details. The tool has 4 parameters (run_dir, now, ttl_days, shadow_canonical) with a required run_dir, but the description doesn't explain the meaning of any beyond implicit inference from the description (e.g., ttl_days likely relates to expiration). This is a gap that forces the agent to guess at parameter semantics.

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: to finalize a run workspace into an immutable, expiring session overlay. It identifies the specific verb ('finalize') and the resource ('run workspace' to 'session overlay'), which helps distinguish it from other migration-related tools. However, it does not explicitly differentiate itself from sibling tools like 'finalize_migration', requiring the agent to infer the distinction.

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 clear context on when to use: artifacts must already exist, and any stage needing an agent fails closed. It implies this is for the final step after research/review artifacts are prepared. It does not explicitly mention when not to use it or list alternatives, but the prerequisites are clearly stated, making the usage context clear.

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