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

Goes well beyond the annotations by explaining the live-fetch behavior, the homepage-only scope, and the semantics of 'not_found.' This aligns with and reinforces readOnlyHint and openWorldHint. It gives the agent exactly the nuanced behavioral context needed to interpret results correctly.

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 compact and front-loaded: the action leads, the operational caveat follows, and the default behavior closes. Every sentence earns its place and nothing is redundant with the title or schema.

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 read-only tool with three parameters and no output schema, the description provides strong behavioral and interpretive detail. The only notable gap is that it never outlines the response shape or fields returned for each linker, leaving the agent to infer output structure from the 'not_found' hint.

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 description coverage is 100%, so the schema already documents all three parameters. The description reinforces the default 'top 8' and max of 15, but adds no meaningful parameter semantics beyond what the schema already provides.

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?

States a precise action: live-verify backlinks by fetching linking domains' homepages and confirming an actual href. It clearly differentiates from index-based sibling tools like backlinks_for_domain by emphasizing 'RIGHT NOW' and 'real-time proof.'

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?

Gives a clear use context: it complements the index with real-time proof. It also provides an important interpretive caveat about 'not_found' meaning only 'no link on the homepage today.' It stops short of explicitly naming sibling alternatives or stating when not to use the tool, so it is not a 5.

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