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

Annotations already cover read-only and idempotent behavior. The description adds significant context: handling brand variants, listing exact output fields, and noting that the answer pack is only available 'when precomputed'. This exceeds annotation coverage and gives the agent actionable expectations.

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 sentences, front-loaded with the core purpose, then output details, followed by explicit usage guidance. Every sentence contributes, with no redundant content.

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 tool with one parameter and no output schema, the description fully covers input semantics, output elements, usage context, and limitations (precomputed answer pack). It is complete for effective tool invocation.

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 describes 'name' as 'Provider name or brand as a user said it,' which is already clear. The description adds concrete examples (ATT, Google Fiber) and implies normalization, reinforcing the parameter's flexibility. This is marginal but useful added value over schema.

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 function: returning a canonical profile of a US internet provider by name, with specific outputs (FCC numbers, technologies, etc.). It also distinguishes itself from sibling tools by emphasizing disambiguation and canonical identity, making its purpose unmistakable.

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 a clear use case: 'Use it to disambiguate providers before making claims about them.' However, it does not explicitly name alternatives or state when not to use it, preventing a 5.

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