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

No annotations are provided, so the description carries full burden for behavioral disclosure. It mentions that 'no results is a real answer' (expected behavior for empty results) and implies different return patterns per argument set, but does not disclose side effects, rate limits, or authentication needs. While it gives useful behavioral hints, it is not fully transparent about all aspects.

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 concise (three sentences) and front-loaded with the main purpose ('Find a paid endpoint'). Every sentence adds distinct value: keyword search tip, empty result behavior, and parameter combination use cases. No redundant or irrelevant information.

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 complexity (4 parameters, all optional, different usage modes) and the absence of an output schema, the description is largely self-sufficient. It explains all parameter semantics and expected return patterns. Minor gap: it does not specify that return values vary by parameters, but this is inferable from the descriptions.

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%, including descriptions for each parameter (`url`, `query`, `domain`, `method`). The description adds significant context beyond the schema: explaining semantic groupings (e.g., `url`+`method` together for full docs, `query` for fastest search, no args for domains). This enhances the agent's understanding of how parameters combine.

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's purpose: 'Find a paid endpoint.' It uses specific verbs and resources ('find', 'paid endpoint') and distinguishes from siblings by focusing on discovery and search, whereas siblings like 'call' and 'balance' imply execution and account queries.

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 provides explicit guidance on when to use each parameter combination: keyword search with `query` is fastest, no results is a valid answer, `domain` lists one service's endpoints, `url`+`method` returns full docs, and no arguments returns allowed service domains. It does not discuss alternatives but covers all usage scenarios clearly.

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