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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description's 'DESTRUCTIVE' and idempotency notes largely restate them. It does add the useful clarification that hanging up a finished call yields a no-op error rather than succeeding silently, which is genuine context beyond the annotations.

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 short sentences, front-loaded with the destructive warning. No redundant restatement of the title and nothing to trim.

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-target mutation whose safety profile is fully annotated and whose parameters are fully documented, this covers what matters, including the idempotent no-op error behavior. Missing only an explicit steer toward siblings like transfer or wrap as alternatives.

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%, including the call UUID / HD_ session id format and the purpose parameter, so the schema carries the parameter burden. The description adds nothing about how call_id maps to live PBX sessions. Baseline 3 applies.

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?

States a specific verb and resource (terminate an active call immediately) and marks it DESTRUCTIVE up front. It's clearly distinguishable from siblings like get_call, desk_transfer_call, desk_wrap_call, and wait_for_call_event.

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 word 'active' implies the when-to-use condition, but it doesn't name alternatives such as desk_transfer_call or desk_wrap_call, or say when not to hang up. Usage is implied rather than explicitly routed.

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