arm_stim

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

With no annotations provided, the description carries full behavioral disclosure burden, and it does so excellently. It explicitly discloses the deliberate expiry behavior ('arming expires deliberately'), the rationale (prevent stale resumption), and recommends disarmament. This is rich behavioral context that the schema cannot convey.

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 compact and front-loaded, with the core purpose in the first sentence and behavior/guidance in the subsequent sentences. The prose about expiry rationale is somewhat verbose for a tool description but earns its place by conveying important behavioral transparency an agent needs. Slightly long but not bloated.

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?

This is a stateful arming tool with security-relevant behavior (expiry), and the description adequately covers the key operational concerns. With an output schema present and full parameter coverage, the description doesn't need to explain return values. The guidance about re-arming and disarming completes the operational picture reasonably well.

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 coverage is 100%, so the schema already documents all three parameters (backend, ttl_sec, session_id) thoroughly. The description adds 'bounded window' context that relates to ttl_sec but doesn't add syntax or format details beyond what the schema provides. Baseline 3 is appropriate when 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 'Permit hardware stimulation for a bounded window', which clearly identifies the verb (arm/permit) and resource (hardware stimulation) with a temporal bound. It distinguishes from sibling tools like disarm_stim (disarming) and send_stim_train (sending a stim), though it doesn't explicitly name the sibling alternative it contrasts with.

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 usage guidance: 'Re-arm as needed, or disarm the moment a block ends.' It explains the deliberate expiry mechanism and implies the recommended workflow. However, it doesn't explicitly say when NOT to use this tool or name alternative tools for specific scenarios, though the context around arming vs disarming is reasonably clear.

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