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

With no annotations, the description carries the full disclosure burden and delivers none: no indication of read-only behavior, authentication requirements, caching or rate limits, or what a caller receives. "Plan fences" implies feature-gating semantics that are never explained.

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?

Five words with zero padding, but the brevity comes from under-specification rather than efficiency. It is front-loaded yet too fragmentary to orient the caller.

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?

No output schema, no annotations, and no parameters means the description is the only source of truth, and it fails to explain what a "plan fence" is or what the response contains. An agent cannot confidently predict the return shape or whether the tool is safe to call.

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 takes zero parameters, and the schema is a fully described empty object, so there is nothing for the description to clarify. Baseline 4 applies for a no-parameter tool.

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?

"Product prices and plan fences" names a data domain but supplies no verb, so it is unclear whether the tool returns prices, evaluates plan gating, or both. It does not distinguish itself from siblings such as authorize or get_remaining, which could plausibly also surface plan-related information.

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?

There is no statement of when to call this versus alternatives like authorize or get_remaining, nor any prerequisite or exclusion. An agent must guess the routing based solely on the word "pricing," and "plan fences" is unexplained jargon.

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