proxy_url

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description is consistent with a non-mutating builder. Beyond the annotations it discloses genuinely useful behavior: the password is a placeholder unless the server allows revealing it, and session/exit-IP semantics. It does not describe the returned string shape, but an output schema exists to cover that.

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?

Front-loaded with the one-line purpose, then a tightly packed block of parameter semantics with zero filler sentences. It is dense but every sentence conveys a distinct, actionable fact.

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 9-parameter, zero-required, zero-coverage tool with an output schema, the description covers the decision-critical semantics (session, targeting, connection type, placeholder password). Only the protocol parameter and any explicit alternative-tool routing are missing, which are minor given the rest.

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 0%, so the description carries the full burden, and it does so for eight of nine parameters: session_id/ttl semantics, two-letter country, region/city/isp codes sourced from list_locations, filter example 'medium', and connection_type branching. The only gap is protocol (http vs socks5), whose enum is self-explanatory but never mentioned.

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 ('Build a NodeMaven proxy string'), which is clearly distinct from siblings like check_proxy, test_proxy_on_site and list_locations. An agent can tell instantly that this constructs a connection string rather than testing or listing anything.

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 concrete when-to guidance on the key decision: omit session_id for a fresh exit IP per request, or supply it to pin an exit for ttl. It also explains the mobile branching (take location codes from list_locations with connection_type='mobile'). It stops short of explicitly contrasting with check_proxy or test_proxy_on_site, so no true exclusions are stated.

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