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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds useful behavioral detail the annotations don't: that results include live status, price, votes, and a link per provider, signaling a self-contained, fairly rich payload. It omits things like result limits or pagination, which keeps it from a 5.

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?

Two short sentences, front-loaded with the core action and result contents, then the optional filter. Nothing redundant.

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 simple read-only listing tool with no required params and no output schema, the description covers what is returned and the single optional filter, which is enough to call it correctly. Differentiation from search_providers and notes on result size are the remaining gaps.

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 100% with an enum for the single optional 'type' parameter, so the schema fully documents it. The description's 'optionally filter by proxy type' merely restates that at a higher level and adds no syntax or semantics beyond the schema.

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 and resource ('All listed proxy providers') and enumerates what each entry carries (live status, price, reader votes, profile link). It does not distinguish itself from sibling tools like search_providers, get_provider, or compare_providers, which is the main gap.

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?

'Optionally filter by proxy type' implies the main usage pattern, but there is no guidance on when to use this listing versus search_providers or get_provider. The agent must infer the choice from the sibling names alone.

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