list_routing_targets

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose that the tool is a listing operation and instructs the agent to defer to the user's choice, which is useful behavioral context. However, it does not mention any side effects (likely none, but not stated), authentication requirements, rate limits, or the exact return format. The description adds some behavioral nuance but leaves significant gaps.

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 well-structured and front-loaded with the purpose, followed by usage guidance and then parameter details. It is reasonably concise, though the parameter list for kinds is somewhat verbose. Every section earns its place, and the overall length is appropriate for the tool's complexity.

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 tool has no output schema, so the description should explain what the tool returns, but it does not. It also fails to explain the purpose of account_id and token_name, and gives no indication of pagination or error behavior. While it provides usage instructions, it is incomplete for a tool with four parameters and no output schema, leaving an agent to guess about return format and omitted parameters.

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 0% description coverage, so the description must explain all parameters. It covers 'kinds' and 'search' with detailed semantics: the allowed subset for kinds and the default set, and the case-insensitive substring behavior for search. However, it completely omits 'account_id' and 'token_name', which are likely authentication/context parameters. This leaves half of the parameters unexplained, making the description insufficient for full parameter understanding.

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 opens with a clear verb and resource: 'List everything a tracking number can be attached or routed to.' This unambiguously distinguishes it from sibling tools that handle phone numbers (search_available_numbers, buy_numbers, etc.) or identity (whoami). The purpose is specific and immediately actionable.

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 gives explicit instructions on how to use the tool's results: present options to the user, never pick for them, and use a numbered list or search for more than four results. This is strong practical guidance. However, it does not explicitly state when NOT to use this tool or name alternative tools for other scenarios, relying on the sibling names to imply that.

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