List proxies

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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so the bar is lower, yet the description adds real value: it discloses what is deliberately withheld ("Never returns usernames, passwords or rotation links") and the implicit free-proxy filter. It stops short of saying whether results include disabled/unchecked proxies beyond the status filter options.

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?

Dense and front-loaded: return fields first, then security exclusion, then the free default, then paging. The trailing "Read-only" duplicates the readOnlyHint annotation and could be dropped; otherwise every sentence carries 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?

With no output schema, enumerating returned fields is a genuine compensating move, and the credential-exclusion note is important for a listing tool. But for a nine-parameter, paginated listing it leaves most filter semantics and pagination limits unexplained, so an agent still has to read the schema for the filters that matter.

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 only 33% across nine parameters, so the description needs to compensate and largely does not. It clarifies only the free flag's default and repeats that search matches name or host; page, pageSize, status, unused, country, blocklisted and proxyGroupId get no added meaning, and the free=true meaning ("only free") is in the schema but the tri-state default is only partly explained.

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 and resource ("Lists proxies you can see") and enumerates the returned fields, so the agent knows exactly what surface this covers. It also carves out the free-proxy default, which helps separate it from find_free_proxies, though the sibling is never named.

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 a crucial default-behavior rule ("Free proxies are left out unless free is true") and notes paging, which shapes how the agent calls it. It never says when to prefer find_free_proxies or get_proxy_health over this listing, so routing is only implied.

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