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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true. The description usefully adds that the call consumes SEO add-on credits and that output rows carry authority and spam score, which the annotations do not convey. It does not explain what the 'destructive' flag refers to (credit consumption vs. data mutation), leaving some ambiguity.

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?

Front-loaded with the core definition, then usage mechanics, then the payoff and cost. Mostly efficient, though the outreach-pitch sentences ('realistic wins', 'before you write a single email') lean promotional rather than informative.

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?

An output schema exists so return values need no explanation, and the cost/citation caveat is covered. The main gap is undocumented limit and refresh semantics for a 4-parameter tool with zero schema coverage.

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 0%, so the description carries the burden. It meaningfully explains competitors (2+ domains required) and exclude_target (your own domain to filter against), but says nothing about limit or refresh, leaving half the parameters undocumented anywhere.

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?

Names a specific operation (link intersect) with a precise definition: domains linking to competitors, optionally filtered against your own domain. An agent can distinguish it from seo_backlink_list, seo_referring_networks, and seo_competitor_gap without opening any schema.

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 clear invocation context (pass 2+ competitor domains; a domain linking to several is the strongest candidate) and explains the exclude_target use case. It does not, however, name alternative sibling tools or state when NOT to use this one.

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