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

No annotations are provided, so the description carries the behavioral burden. It discloses that the tool is FREE, filters by current Verified qualification, and excludes full-cache and per-URL metric outputs. It does not mention auth, rate limits, or response shape, but the read-only listing behavior is adequately conveyed for this simple tool.

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?

Three short sentences, each earning its place: the first states scope and cost, the second and third route to alternatives. Key information is front-loaded and there is no filler.

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 zero-parameter, no-output-schema list tool, the description is complete. It defines what is returned, when to use it, and how it differs from the relevant siblings. No additional context is needed to invoke it correctly.

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?

With zero parameters, the input schema is already complete and there is nothing for the description to add about parameter meaning. The baseline of 4 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?

The description uses a specific verb and resource: 'List only APIs that currently qualify for the Verified routing tier.' It clearly differentiates from sibling tools by stating what it is not: not the full cache and not per-URL metrics.

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 explicitly says 'Prefer over list_discovered_apis' and 'Prefer over get_api_stats', and provides the conditions that select this tool: wanting reliability-filtered endpoints or a pass/fail Verified set. This gives an agent direct routing guidance.

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