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

With no annotations, the description carries the behavioral burden. It discloses that broader CLLI prefixes can return more rows and explains the thousands aggregate semantics, but it does not cover pagination, row limits, or other operational constraints.

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 front-loaded with the core operation, followed by usage context, input behavior, return fields, and field semantics. Each sentence contributes useful information, especially because there is no output schema.

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 list tool with no output schema and no annotations, the description supplies meaningful return-field context and explains the thousands aggregation. It is nearly complete, though it omits pagination or row-limit expectations.

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 already 100%, so the baseline is 3. The description still adds useful meaning by explaining that the input can be a 6- to 11-character CLLI prefix and that broader prefixes increase the row count.

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 begins with a specific verb and resource: 'List prefixes routed via a tandem switch CLLI.' It clearly distinguishes this tool from prefix-oriented siblings like list_lata_prefixes and list_ocn_prefixes by tying the result set to a tandem CLLI.

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?

It gives clear usage context: routing/interconnection questions or when the user has a tandem CLLI and wants all served prefixes. It does not explicitly name when not to use it or point to the closest sibling alternatives, so it stops short of full routing guidance.

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