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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The word "Replace" usefully signals a full-overwrite of the existing list rather than an append, but the description does not say whether an empty list clears the config, how URLs are validated, or whether an in-flight connection drops on replacement.

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?

A single front-loaded sentence with zero filler, so nothing needs trimming. It is concise to a fault: the brevity is what leaves the parameter and usage gaps unaddressed.

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 mutating config tool with two parameters, one of them entirely unmentioned in the description and only weakly described in the schema, this is under-specified. With no output schema the description should at least say what state results after replacement, and it does not.

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 only 50%: proxyUrls is documented as a bare "Proxy URL" item type, and organizationId only as "Approved workspace id only." The description compensates for neither — it never mentions organizationId scoping, ordering/precedence of URLs, or whether the array must be non-empty.

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 states a specific verb ("Replace") and resource ("proxy URL list"), which lets an agent distinguish this write tool from get_proxy_config and test_proxy_config by name alone. It stops short of explicitly naming those siblings as alternatives, so a 4 rather than a 5.

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?

There is no guidance on when to use this instead of test_proxy_config (to validate) or get_proxy_config (to inspect), and no prerequisites such as required permissions or whether the config takes effect immediately. "Replace" hints at full-overwrite semantics but no alternatives or exclusions are stated.

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