proxy_set_host_upstream

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the core effect—traffic to the hostname uses the specified proxy instead of the global one—but omits details about persistence, idempotency, precedence over existing overrides, or the revert path.

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-load the action and effect with no wasted words. The description is efficient and immediately understandable.

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?

As a simple setter, the description captures the essential behavior, but the absence of annotations and output schema leaves gaps: whether an existing override is replaced, whether the setting persists, and how to undo it are not addressed. The no_proxy parameter's behavioral role is also left to inference from the schema.

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 description coverage is 100%, so all parameters are already documented in the schema. The description adds only the per-host context for hostname and does not elaborate on no_proxy or proxy_url semantics beyond what the schema provides.

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 ('Set') and a precise resource ('per-host upstream proxy override'), immediately distinguishing it from global proxy configuration. The second sentence reinforces the scope by contrasting the per-host behavior with the global one.

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 clearly communicates when to use this tool: when a specific hostname should bypass the global upstream proxy. However, it does not explicitly name sibling alternatives such as proxy_set_upstream or proxy_remove_host_upstream, nor does it provide explicit when-not-to-use criteria.

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