upgrade

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that the tool returns a link and instructs the agent to give it to the person without opening it or paying. This discloses the expected agent action, but it does not explicitly mention any side effects (e.g., whether a Stripe session is created) or the nature of the link (one-time vs. recurring). Given the simplicity of the tool, this is a solid level of transparency.

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 a single, well-structured sentence that front-loads the primary action ('Get a Stripe Checkout link') and includes essential instructions without redundancy. Every phrase earns its place, making it concise 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?

For a zero-parameter tool with a clear output (the link), the description fully covers what an agent needs: the purpose, what to do with the result, and a key condition (no limit on reviews). There is no missing information that would prevent correct invocation or handling.

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 and the schema coverage is 100% (since there are none). The description does not need to explain parameters, but it adds meaningful context by stating that the link is for a subscription with no review limit. With no parameters to describe, the baseline of 4 is appropriate, and the description does not leave any gaps.

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 identifies the tool's action ('Get a Stripe Checkout link') and its resource (subscription to Phyll Pro), and it differentiates the tool by specifying the upgrade purpose. It is specific and unambiguous, leaving no doubt about what the tool does.

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 gives explicit instructions for how to use the output: 'Give the link to the person; never open it or pay on their behalf.' This clearly defines when to use the tool (when a user wants to subscribe) and what not to do, making the usage context and boundaries explicit.

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