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

With no annotations, the description carries the behavioral burden. It explicitly says this is 'registration only' and that the scoring pipeline sends the mail, which is non-obvious and prevents a common misconception. It could add more about duplicates, confirmation behavior, or permission requirements, but the core behavioral disclosure is strong.

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 and front-loaded with the purpose. The 'INFLUENCE' prefix is somewhat cryptic and adds little, but the two sentences otherwise earn their place by explaining both the function and the registration-only behavior.

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 simple registration tool with three parameters and no output schema, the description covers the main purpose, the events, and the critical limitation that it does not send the email itself. It is reasonably complete, though it could mention the expected return value or duplicate 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 schema already documents the 'events' values and default, and the 'context' field. The description adds natural-language equivalents ('score changes, band changes, or a check closing') but does not add substantial new semantics for the required 'slug' parameter beyond implying it identifies the listing.

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 what the tool does: it records a request to be notified when a listing changes (score, band, or check closing). It uses a specific action and resource, though it does not explicitly differentiate itself from sibling tools like add_to_list or create_list.

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 clear context for when to use the tool: when you want to be told about changes to a specific listing. It also clarifies that this is only registration. However, it does not name alternative tools or state when not to use it.

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