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

The description adds a genuinely useful trait beyond the annotations: 'Costs SEO add-on credits,' which explains the non-readOnly profile. But it never addresses destructiveHint=true or idempotentHint=false — a 'lookup' being flagged destructive is surprising and the description should reconcile that. With annotations already carrying the safety profile the bar is lower, so a 3 fits.

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 compact sentences with the purpose front-loaded, followed by the concrete data returned and then the cost caveat. Nothing is wasted, though the em-dash clause reads slightly as a marketing tagline rather than operational guidance.

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-value detail is unnecessary, and the description correctly summarizes what comes back (tech stack, rank, contact info). What it omits is any parameter guidance for a 2-parameter tool with 0% schema coverage, which is the piece an agent most needs.

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% and neither of the two parameters ('target', 'refresh') is mentioned anywhere in the prose. The description gives no hint about the expected domain format, whether 'target' accepts URLs or bare domains, or what 'refresh' does versus a cached result. This is the tool's largest gap and the description does not compensate for the schema.

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 concrete resource ('Website technology + contact lookup') and enumerates its outputs: tech stack, authority rank, and public contact info. It distinguishes itself from audit-oriented siblings like seo_technical_audit by framing itself as competitive/sales intelligence rather than a diagnostic. It stops just short of a 5 because the phrasing is nominal ('lookup') rather than an explicit verb like 'Retrieve the technology stack and contacts for a domain.'

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?

It hints at intent with 'competitive and sales intelligence' and notes it is an 'SEO Intelligence add-on,' which implies when it is worth the cost. However, it names no alternatives and gives no exclusions (e.g., when to prefer seo_audit or seo_full_analysis), so the agent must infer the routing decision.

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