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

Annotations already signal readOnlyHint and openWorldHint, and the description adds useful behavioral context: the returned payload composition and the row limits by tier. It does not mention pagination or sorting, but the disclosed details go beyond the structured annotations.

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 sentences carry the core output description, tier limits, and a pointer to an alternative tool. The most identifying 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?

With no output schema, the description adequately explains what the caller will receive: total inlink count and a ranked list with authority and outbound link counts. The tier limits add practical context, though sorting or field names are not specified, which is a minor gap for a single-parameter read tool.

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 fully documents the single 'domain' parameter with an example ('stripe.com'), so schema coverage is 100%. The description adds no additional parameter-level semantics beyond restating that it operates on a domain.

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 names a specific action and resource: 'Full backlink payload for a domain' with concrete content ('total inlink count plus the ranked list of linking domains'). It also distinguishes itself from the sibling domain_authority_score by noting that tool covers only the headline number.

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 provides an alternative: 'use domain_authority_score for just the headline number.' It also sets expectations around tier-based row limits, helping the agent decide whether this tool is appropriate for the user's plan.

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