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

Annotations already declare read-only and idempotent hints, so the description doesn't need to discuss safety. It adds useful behavioral context by enumerating the data included (providers, locations, tech mix, vintages) and confirming there is no geographic filtering below national level.

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?

Two concise sentences deliver the full value: the first enumerates the data dimensions, the second states the intended use case. No fluff 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?

With no output schema, the description carries the burden of explaining return values, and it lists the main categories (providers, locations, tech mix, vintages). The phrase 'filing vintages held' is slightly technical, but sufficient for an overview tool with no 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 tool has zero parameters, so the schema provides no input guidance. Baseline is 4; the description appropriately focuses on output content rather than inputs, leaving no parameter semantics gap.

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 what the tool provides: US telecom market data at national scale, including providers, locations, technology mix, and filing vintages. It distinguishes itself from local/area-focused siblings by emphasizing 'national scale' and 'market context,' though it lacks an explicit verb like 'get' or 'list.'

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 context for when to use it: for questions about the US broadband industry, the fiber transition, or market size. It does not explicitly name alternatives or say when not to use it, but the national vs. local distinction implies the boundary.

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