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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description does contribute return-side context by disclosing that results include remaining traffic and connection credentials — useful since there is no output schema. It stops short of noting credential sensitivity, pagination, or result size.

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 short sentence with no filler, and the scope ('of the account') leads. It reads as a fragment rather than a full sentence, which is a minor structural weakness but does not impede comprehension.

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 zero-parameter read-only tool, the annotations cover safety and the description covers the payload (proxies, remaining traffic, credentials). With no output schema present, it would help to know whether credentials are returned in plaintext or whether the list is paginated, but nothing essential for correct invocation 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?

The tool takes zero parameters, and the schema confirms an empty properties object at 100% coverage, so the baseline of 4 applies. The description adds no parameter detail because there is none to add.

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 names a specific resource and scope ('All proxies of the account') and even characterizes what comes back ('remaining traffic and connection credentials'), so an agent knows this is a retrieval of the account's proxy inventory rather than a purchase (buy_proxy) or extension (extend_proxy). It is a noun phrase with no explicit verb, but 'All proxies of the account' is unambiguous as a listing operation.

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 call this versus alternatives such as get_credentials (which overlaps with the 'connection credentials' mentioned here) or buy_proxy/extend_proxy. No preconditions, no exclusions, no routing cues; the agent must infer usage entirely from the tool name.

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