register_agent

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

With no annotations, the description carries the full burden of behavioral disclosure. It does reveal a significant side effect: decisions will be accumulated into a trajectory that others can observe. However, it does not mention other behavioral traits such as whether registration is mandatory, if it can be undone, or any permissions or side effects beyond trajectory logging. This is partial transparency but not comprehensive.

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 exceptionally concise: two short sentences that front-load the primary action ('Register in this environment') and add one valuable behavioral consequence. Every word serves a purpose, with no redundancy or filler. It is an excellent example of economy in tool descriptions.

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 that the tool is simple (no required parameters, no output schema), the description is minimally sufficient, but it leaves some gaps. It does not explain the relationship to other tools like create_ise_session or create_decision, nor does it explicitly state that registration should occur before making decisions. The mention of a trajectory implies intended usage, but the description could be more complete for an agent to use it confidently.

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 input schema already fully describes both parameters (is_test and region_code) with 100% coverage, so the baseline is 3. The description adds no additional parameter-specific meaning beyond the schema; it only discusses the tool's overall purpose and effect. Since the schema handles parameter semantics adequately, this score is appropriate.

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 that the tool registers an agent in the environment, using the specific verb 'Register' and resource 'environment'. It explains a consequence (decisions accumulate into an observable trajectory), but it does not explicitly differentiate from the sibling tool 'register_tool' or other similar tools, though the name and wording strongly imply agent registration.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention prerequisites, order of operations, or situations where it should not be used. It only states what registering does, so the agent is left without clear direction on when to invoke it.

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