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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that: results are 'verified' carrier-specific codes or portal steps, and the user's number is injected so the agent needn't construct it. It stops short of saying what happens for an unrecognized carrier or in what shape the steps come back.

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 sentences with no padding: the first front-loads what the tool returns, the second front-loads the interaction prerequisites. Every clause carries actionable information.

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 two-parameter read-only lookup with no output schema, the description covers what is produced (codes or portal steps), that the number is filled in, and the conversational setup required. Minor gaps remain around unknown-carrier behavior and how the missed/all-calls choice is communicated to the tool.

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 baseline is 3; the description reinforces that the carrier is captured in the user's own words and that the target number is the user's SkipCalls number. However, it instructs the agent to capture a missed/conditional versus all-calls choice that has no corresponding parameter, leaving the agent unsure how that decision reaches the tool.

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 (Get) and a specific resource (verified carrier-specific call-forwarding codes or portal steps), plus the key qualifier that the user's SkipCalls number is pre-filled. This is distinguishable at a glance from siblings like runForwardingTestCall or transfer_numbers_list, which also touch forwarding.

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?

Gives an explicit precondition sequence: ask the user to name or confirm the carrier and to choose missed/conditional versus all calls before invoking. It does not name an alternative tool or state when not to use this one, but the preconditions are clear enough that an agent knows how to reach the call correctly.

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