List newsletter subscribers

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

With no annotations provided, the description carries the full burden. It discloses the most important behaviors: read-only, no credit consumption, and the returned fields. It does not mention pagination or ordering, but the schema covers those mechanics.

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?

Two concise sentences, front-loaded with the verb and resource, followed by essential caveats and a filter example. Every sentence earns its place.

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 list operation, the description explains the purpose, return fields, read-only nature, credit implication, and a filtering example. Pagination and page size are documented in the schema, so the description is complete without duplicating that information.

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 describes all four parameters with 100% coverage, so the baseline applies. The description adds only a minor usage hint about app_lead, which does not materially enhance the parameter semantics beyond what the schema already provides.

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?

Clearly states a specific action (List) on a specific resource (newsletter subscribers), includes the fields returned, and is distinct for this project. It is unambiguous and immediately distinguishes the tool from siblings.

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 notes that it is read-only and does not consume credits, which is a key usage consideration. It also gives a concrete filtering example for app_lead. Since no sibling tool lists newsletter subscribers, explicit alternative guidance is not needed.

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