bevigil_get_hosts

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds behavioral context by stating it 'Returns a list of unique hostnames/domains extracted from the app,' which clarifies the output nature. No contradiction with annotations.

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 succinct sentences: the first states the purpose, the second gives the use case, and the third covers requirements and output. No wasted words, and critical information is front-loaded.

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?

Given the tool's low complexity, complete parameter schema, and rich annotations, the description is fairly complete. It covers purpose, use case, requirements, and return type. It does not mention pagination behavior explicitly, but the schema handles that, so the description is adequate for an agent to select and invoke 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?

Schema description coverage is 100% for all three parameters (package_id, limit, offset), so the schema already explains them thoroughly. The description adds minimal parameter-related value beyond reinforcing that package_id is required; it does not elaborate on limit/offset semantics beyond what the schema provides.

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 action ('Get hostnames and domains') and the resource ('Android application's code'). It explicitly differentiates from sibling tools like bevigil_get_subdomains and bevigil_get_urls by focusing on hostnames/domains and their use case (discovering backend servers, APIs, third-party services).

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?

Provides clear use context: 'Use this to discover backend servers, APIs, and third-party services that a mobile app communicates with.' It also specifies a prerequisite ('Requires an Android package ID'). However, it does not explicitly mention alternatives or when not to use it, though the sibling tool names imply differentiation.

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