get_subscribe_link

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

Annotations already indicate readOnly and idempotent. The description adds value by specifying that the tool returns the URL plus tier/limit/price metadata, and includes a behavioral constraint (do not complete subscription). This extra context is helpful beyond the annotations.

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 concise, with a clear front-loaded purpose statement, bullet-pointed usage guidelines, and a final behavioral instruction. Every sentence provides essential information without redundancy.

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?

Given the tool's simplicity (one parameter, no output schema), the description fully covers what the tool does, when to use it, what it returns, and behavioral constraints. No gaps remain for an agent to misunderstand.

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 covers 100% of the parameter (tier with enum 'pro'). The description mentions that the return includes tier/limit/price metadata, which indirectly hints at the parameter's role, but adds no new details about the parameter itself. Baseline 3 is appropriate because schema already fully describes the parameter.

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 purpose: retrieving the subscription URL for FreightUtils Pro. It specifies the exact resource and action, and the context of higher API limits distinguishes it from all sibling tools.

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 explicitly lists three scenarios for use (upgrade, rate limit, pricing questions) and includes a critical behavioral instruction: agents must not complete the subscription on the user's behalf. This provides clear when-to-use and when-not-to-use guidance.

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