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

With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: decisions accumulate into an observable trajectory, which is important context. However, it doesn't disclose whether registration is idempotent, whether it has side effects beyond trajectory creation, or what happens if called multiple times. The description adds some value but leaves meaningful behavioral gaps.

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 sentences with zero waste. The core action is front-loaded ('Register in this environment'), and the consequence is stated in one additional sentence. Every word 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?

For a single-parameter tool with no output schema, the description is mostly adequate. It explains the purpose and the key consequence (trajectory accumulation). However, it doesn't clarify whether registration is required before other tools, whether it can be called multiple times, or what the response indicates. These are minor gaps for a simple registration tool, but they prevent a higher score.

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 fully documents the region_code parameter. The description adds no parameter-specific information beyond what the schema provides. Baseline 3 is appropriate since the schema does the heavy lifting.

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 states a clear verb and resource: 'Register in this environment.' It also adds a meaningful consequence ('Your decisions will accumulate into a trajectory that others can observe'), which distinguishes it from generic registration tools. However, it doesn't explicitly differentiate from sibling tools like register_tool, so it loses a point on sibling differentiation.

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 implies when to use it: at the start of an environment session, before making decisions. It says 'Register in this environment' and explains the trajectory accumulation, which gives context. But it doesn't explicitly state when not to use it or mention alternatives (e.g., register_tool), so usage guidance is implied rather than explicit.

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