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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior, so safety is covered. The description adds minimal behavioral context beyond the tool's name, providing no details on matching semantics (e.g., exact vs partial match), result scope, or pagination.

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 a single concise sentence that is front-loaded with the verb and resource. There is zero redundant phrasing; it earns its place as an efficient summary of the tool's purpose.

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 simple one-parameter search tool with strong annotations and an output schema (not shown), the description is minimally viable. However, it lacks any usage context or parameter elaboration, so an agent might need additional inference about expected input format or result structure.

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 0% and the description does not compensate. It merely restates the parameter name ('nameserver') without explaining expected format (e.g., hostname, IP), matching behavior, or any constraints. The single required parameter is left entirely self-explanatory.

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 'Search scans by nameserver' uses a specific verb (Search), identifies the resource (scans), and specifies the search criterion (nameserver). It clearly distinguishes from sibling tools like search_by_ip or search_by_registrar by uniquely indicating the nameserver-based lookup.

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 usage is implied: use this tool when you need to find scans associated with a nameserver. However, there is no explicit guidance on when to choose this over other search_by_* siblings, no exclusions, and no alternative suggestions.

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