compare_domain_authority

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

Annotations already declare the tool as read-only, non-destructive, idempotent, and open-world. The description adds valuable behavioral context beyond these annotations by revealing the cost ($0.02 USDC) and the ranking behavior of the output. It also clarifies the 'open-web' scope of the authority metric. This supplements the annotation coverage effectively.

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 conveys the action, scope, and cost without any fluff. Every word contributes to the tool's understanding, achieving high information density in a compact format.

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 a single parameter, a simple read-only operation, and strong annotations, the description is complete. It covers the action, domain count range, ranking behavior, and cost. The absence of an output schema is compensated by the description's 'rank the results' phrasing, which implies a structured output. No critical information is missing for an agent to invoke the tool 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?

The schema already provides 100% coverage for the only parameter ('domains') with a clear description ('Two to twenty domains or URLs') and constraints (min/max items). The tool description adds minimal additional parameter meaning beyond restating the range ('2 to 20 domains'). Since the schema does the heavy lifting, a baseline score of 3 is appropriate.

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 ('compare'), a clear resource ('domains'), and an outcome ('rank the results'), making the tool's purpose unambiguous. It distinguishes itself from the sibling 'get_domain_authority' by focusing on multi-domain comparison and ranking. The mention of 'open-web SEO authority' adds specificity.

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 clearly indicates when to use this tool: when you need to compare and rank SEO authority for 2 to 20 domains. It implies a multi-domain use case, setting it apart from single-domain tools, but it does not explicitly name alternatives or provide exclusionary guidance. This is clear context without explicit 'when-not-to-use' advice.

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