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

No annotations are provided, so the description carries the full burden. It states the action (rank) but does not disclose return format, side effects, permissions, or any other behavioral traits. An agent cannot tell if this is a read-only operation or what the output will look like.

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?

The description is a single, front-loaded sentence that directly states the action and criteria. There is no redundant wording or unnecessary detail, making it fully concise and well-structured.

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 tool with no parameters and no output schema, the description covers the core purpose but omits return value expectations and any edge conditions (e.g., what counts as 'healthy' or 'free'). It is sufficient for basic understanding but not fully complete for an agent to know what to expect from the output.

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 has zero parameters, so the baseline is 4. The description adds no parameter-specific information, but none is needed since the schema is empty. The description does not mislead or omit anything relevant to inputs.

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 uses a specific verb ('Rank') and identifies the resource ('healthy free providers') plus the ranking criteria ('priority and latency'). It clearly distinguishes the tool's purpose from siblings like provider_probe (which probes) and provider_list (which lists).

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?

The description implies the tool should be used when you need an ordered list of healthy free providers by priority/latency, but it does not explicitly state when to prefer this over alternatives or provide exclusions. Sibling tools like provider_candidates or provider_probe suggest different use cases, but no direct comparison is given.

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