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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety needs no restating. The description does add real behavioral value: result ordering (regular prices first, lowest first; first-purchase offers and upper bounds flagged afterwards) and per-result provenance (proxyrange.com link plus price-check date). However, it says nothing about empty-result behavior, whether filters are ANDed, or how one-sided filters like maxPriceUsd interact with basketGb.

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 resource and its filter set, which is good. But the single sprawling parenthetical re-lists all seven parameter dimensions already fully documented in the schema, so a meaningful share of the text does not earn its place.

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 an output schema present, the description need not explain return shapes, and it correctly confines itself to scope, ordering, flagging and provenance. For a zero-required-parameter read tool that is close to complete; only the omission of filter-combination semantics and sibling routing keeps it from a 5.

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% and the schema already explains every parameter, including the enum groupings and units. The description's parenthetical largely restates those same dimensions rather than adding syntax or interaction rules; the one genuinely additive note is that ordering and flagging relate to the 1/10/100 GB baskets. Baseline 3 applies.

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 the resource precisely — residential proxy providers filtered by buyer requirements — and enumerates the filter dimensions (targeting, payment, ID check, expiry, price cap, sourcing, minimum purchase, session length). It reads as a noun phrase with no explicit verb ("find") and never distinguishes itself from siblings like compare_providers or cheapest, but the scope is unmistakable.

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?

No statement of when to use this tool versus the six siblings (cheapest, compare_providers, get_provider, monthly_picks, shared_infrastructure, sourcing_check). An agent must infer from the name alone that this is the filter/search entry point rather than a comparison or lookup tool.

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