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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds valuable behavioral context: it explains the fallback to Free tier when no active or past-due subscription exists, and reassures that payment-processor credentials are never returned. This goes beyond the annotations and gives the agent confidence about edge-case behavior.

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 three short sentences, each conveying a distinct piece of information: the main action, the fallback behavior, and the security guarantee. It is front-loaded with the core purpose and has zero filler, making it effective and easy to parse.

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 an output schema present, return values are already specified, and annotations cover the operational profile. The description completes the picture by explaining the fallback logic and the non-return of sensitive data. For a single-parameter, read-only tool, nothing needed for correct invocation is missing.

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 input schema has 100% coverage for the single parameter businessId, including a pattern and descriptive text. The description adds no extra parameter-specific meaning, but the schema already fully documents it, so the baseline of 3 is appropriate.

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 retrieves the current billing plan and quota limits for a specific tenant-owned business, using a specific verb ('Get') and a concrete resource. It distinguishes itself from sibling tools by focusing on subscription data, and the fallback note adds specificity about the returned state.

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 implies this tool is for retrieving subscription information for a single business, but it does not explicitly compare to alternatives like get_business or list_businesses, nor does it state when to prefer this over other tools. The purpose makes the use case clear, but explicit routing or exclusion guidance is absent.

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