List technologies across many domains

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

Beyond the readOnlyHint annotation, the description adds meaningful behavioral details: duplicate and www. variants collapse, credits are charged per domain with data, malformed domains are free, and raising per_domain does not cost extra credits. These are non-obvious traits an agent would not otherwise know.

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 longer than average but every sentence carries actionable information. It is front-loaded with purpose and usage guidance, followed by edge-case behavior and pricing, with no filler or repetition.

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?

The description covers the tool's purpose, main alternative, parameter nuances, batching behavior, deduplication, and credit cost. The only mild gap is that the 'compact table' return format is not specified in more detail, but the examples and references to lookup_domain_technologies provide enough orientation.

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 coverage is 100%, so the baseline is 3. The description goes further by clarifying that category means the part before the slash in lookup_domain_technologies output and that the sub-category after the slash matches nothing, plus that per_domain affects only context, not cost. This adds real value beyond 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 opens with a specific verb and resource: 'Look up the technologies on up to 20 domains in ONE call', and immediately names the sibling tool it should not be confused with. It clearly distinguishes itself from lookup_domain_technologies by scope and level of detail.

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 says to prefer this tool over repeated lookup_domain_technologies calls whenever several domains are in hand, and tells the agent to switch to lookup_domain_technologies when full detail on a single domain is needed. It also explains when category should be used and when it should be omitted.

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