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

The description adds behavioral context beyond the annotations. It explicitly states idempotency (matching idempotentHint), explains that closing never creates a payment (a unique side-effect not in annotations), and details what gets terminated (CDP relay and upstream browser). It also provides transport-level guidance on the lease bearer, which is beyond the structured annotations. No contradictions.

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 three sentences, compact, and front-loaded with the core action. Each sentence adds value: action and scope, payment side-effect, and transport security. No filler or redundant wording.

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 simple single-parameter destructive tool with rich annotations (idempotent, destructive), the description covers the essential behavior, side effects, and security considerations. It doesn't mention the return value or error handling, but an output schema exists. It could also explicitly state when to use it, but the core usage is clear enough. Overall, it's nearly complete.

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 schema has one required parameter (session_id) with a regex pattern but no textual description, giving 0% schema description coverage. The description mentions 'for one lease' and refers to the lease bearer, implying session_id is the lease identifier, but it does not explicitly state what session_id represents. It also cautions not to place the lease bearer in tool arguments, which could confuse whether session_id is the bearer. More explicit parameter explanation would help.

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 specific verb ('terminate'), a specific resource ('CDP relay and upstream browser'), and a specific scope ('for one lease'). It clearly distinguishes from sibling tools like connect and status by describing the closing action. The phrase 'Idempotently terminate' also conveys the operation's nature.

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 a critical usage guideline: 'Supply the lease bearer on the HTTP or MCP transport; never place it in tool arguments.' It also notes that closing never creates another payment, implying it's a cleanup operation. However, it does not explicitly state when to use this tool over its siblings (e.g., when a session is done) or mention any prerequisites like an active lease.

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