Set Proxy Default Targeting

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

Beyond the annotations (non-read-only, idempotent), the description discloses that this changes the STORED default—a persistent side effect—and explains the billing implications (2x on own allocation vs included on residential_premium). This is exactly the behavioral context an agent needs beyond the structured 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?

Three sentences, zero filler. The core action is front-loaded, followed by billing nuance, then the key persistence warning and routing to the sibling tool. Every sentence earns its place.

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?

The description covers what the tool does, the persistent side effect, billing impact, and the alternative for one-off use. There is no output schema, but nothing essential for correctly selecting or invoking the tool is missing.

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 schema already documents each parameter clearly. The description adds value by explaining the billing consequences of cities/ASNs versus country-only, and by noting that state/zip targeting is only available via the alternative tool, which helps an agent decide what to pass.

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 uses a specific verb ('Persist') and resource ('default geo-targeting on an existing proxy sub-user'), making the action unmistakable. It also distinguishes itself by contrasting with virtualsms_generate_proxy_endpoint, which is the one-off connection-string tool.

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?

It explicitly states when to use this tool (persisting a stored default) and when not to ('For a one-off connection string ... use virtualsms_generate_proxy_endpoint instead'). It also gives billing context that affects whether this tool is the right choice depending on the pool type.

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