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

The description thoroughly explains side effects: it creates a pending signup, sends a confirmation email, stores name/email/phone/case number, includes an unsubscribe link, and does not share with attorneys. It clarifies that monitoring only starts after the user clicks the link, that count-based detection means moved hearings don't trigger alerts, and that a third active case returns a plain message. This exceeds the annotations' basic readOnly/destructive hints and fully informs the agent of the tool's 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 long but every sentence delivers essential information. It is logically organized: purpose first, then safety constraints, then detailed behavior, storage, limits, and scope. Key warnings are emphasized with all caps, and the formatting makes it easy to scan. Nothing is redundant or tangential.

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 complexity, the description covers all critical aspects: purpose, side effects, limitations (count-based alerts, free account cap), privacy (no sharing), required versus optional inputs, explicit instructions for interacting with the user, and regional scope. It also addresses edge cases (dormant signup, third active case) and provides a fallback to another tool (search_cases_by_party). This is a complete and self-contained description.

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?

Although the input schema has no parameter descriptions, the text explains every parameter: name and email are stored, phone is optional, and case_number is required ('A case number is required — subscribe to a case, not to a person's name'). It also clarifies that email is used for sending alerts and that the user must confirm the email address aloud. This fully compensates for the schema's lack of descriptions.

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 purpose: 'Sign the USER UP for email alerts when a North Carolina (NC) case changes.' It explicitly distinguishes itself from lookup tools ('It is not a lookup'), uses a specific verb ('sign up'/'subscribe'), and identifies the resource ('case updates'). The additional details about sending a confirmation email and storing information further clarify 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 provides explicit usage guidance: it tells agents to only subscribe the person they are talking to, to confirm details before calling, to use search_cases_by_party if only a name is available, and to subscribe to a case number rather than a person's name. It also specifies the geographic scope ('NC only') and warns against promising alerts for moved hearings or disposition changes. This covers both when to use and when not to use the tool.

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