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

Annotations already declare readOnlyHint and openWorldHint, but the description adds valuable context by stating 'No auth required' and specifying the return content ('pricing, tier, and availability'). This goes beyond the annotations without contradicting them, giving the agent practical knowledge about access and output.

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 three sentences, each serving a distinct purpose: stating the action, providing usage context, and disclosing output and auth requirements. It is front-loaded with the core purpose, maintains brevity, and avoids redundancy. 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 essential aspects for a search tool: what it searches, when to use it, what it returns, and auth requirements. The output schema handles return value structure, and the parameter schema handles argument details. The only minor omission is explicit mention of pagination/sorting defaults, but this is not critical given the existing structured metadata.

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 input schema has 100% coverage with clear descriptions for all five parameters (limit, query, emotion, maxPrice, minPrice). The tool description does not add additional parameter-specific semantics, but it sets expectations about the output (pricing, tier, availability) that relate to the price parameters. With full schema coverage, a baseline of 3 is appropriate.

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 states a specific verb and resource: 'Search domains available for rent on Popdot AI.' It also lists three concrete use cases ('verifiable web identity, temporary deployment address, persistent web presence') that clarify what the tool accomplishes. This clearly distinguishes it from siblings like check_availability or rent_domain, which have different purposes.

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 'Use this when an agent needs a web address' and enumerates the scenarios. This provides clear context for when to invoke the tool. It does not explicitly name alternatives or exclusions (e.g., 'use check_availability for specific domain checks'), but the 'when' guidance is strong enough to avoid ambiguity in most cases.

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