Search domains

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

Annotations already cover safety (read-only, idempotent, non-destructive). The description adds valuable behavioral context: each page costs one API query, IP-only fields cause syntax errors, and the distinction between filter and query modes. This goes beyond what annotations provide, though it doesn't detail pagination behavior or error handling further.

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 efficient, starting with the core purpose, then the field list, then the critical distinction from IP search, then the requirement, and finally cost. Every sentence adds value with no redundancy or fluff.

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 tool with 5 parameters, no output schema, and a nested filter object, the description covers all essential aspects: what fields are valid, how to choose between filter and query, the cost per page, and the distinction from sibling tools. Return format is handled by the response_format parameter, so nothing critical is missing for an agent to invoke it correctly.

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 has 100% description coverage for each parameter, so baseline is 3. However, the description adds meaning beyond the schema by enumerating valid field names (apex_domain, keyword, tld, etc.) and clarifying that filter and query are mutually exclusive alternatives, which is not enforced by the schema itself. This compensates for the schema's generic propertyNames constraint.

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 clearly states the tool searches the domain dataset using either a structured filter or DSL query, and explicitly distinguishes it from the IP search tool by noting IP-only fields cause errors and belong in securitytrails_search_ips. This makes the tool's purpose unambiguous and distinct from siblings.

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 explicitly says when to use this tool (for domain dataset), when not to (IP-only fields), and directs to the correct sibling. It also states the exact requirement that exactly one of `filter` or `query` must be provided, which is critical usage guidance.

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