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

Annotations already flag destructiveHint=true and idempotentHint=true, so safety profile is covered. The description adds genuinely useful context beyond that: the carrier number survives the operation, which is the key side-effect an agent must know before invoking a destructive tool.

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 terse sentences with zero waste. The primary action is front-loaded and the critical caveat follows immediately.

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 one-param destructive tool with strong annotations and a complete schema, the description covers the essential ambiguity (removal vs. cancellation). Only minor gaps remain, such as what happens if no binding exists or what the response confirms, though the idempotent hint partially covers the former.

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 single 'number' parameter is fully documented in the schema (100% coverage) including the E.164 pattern and leading '+'. The description adds nothing about the parameter, so baseline 3 applies since the schema carries the burden.

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 ('Remove the routing binding') and immediately delineates scope with 'does not release or cancel the carrier number.' This distinguishes it from number-lifecycle operations, though it doesn't explicitly name the sibling bind_number that would be its natural counterpart.

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 negative clause implies the use case (detach routing while retaining the number), but the description never states when to choose this over alternatives like bind_number or a number-release flow. Usage is inferable rather than explicit.

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