List subscribers

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description's added value is the auth scope ('view_sales') and the note that no local approval is needed; the 'read only' clause merely repeats the annotation, and no pagination or return behavior is described.

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?

It is compact and front-loads the purpose before the endpoint and scope details. The clause about approval is slightly opaque jargon, but nothing is padded or repeated verbatim.

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?

There is no output schema, so the description could reasonably say more about the returned subscriber shape or pagination contract, though page_key is documented in the schema. Endpoint and auth scope are given, which covers the essentials for a filtered list read, but gaps remain.

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?

Schema description coverage is 100%, so all four parameters (email filter, account, page_key, product_id) are already documented in the schema. The description adds no parameter-level syntax, format, or interaction detail beyond restating the endpoint path, so the baseline of 3 applies.

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 names a specific verb and resource ('List subscribers') and pins it to the concrete endpoint GET /products/:product_id/subscribers, which tells an agent exactly what data class it returns. It does not, however, distinguish itself from the sibling get_subscriber beyond the implicit singular/plural split.

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 stated scope ('view_sales') is a real prerequisite that tells the agent what authorization the call needs, which is useful context. Beyond that there is no when-to-use guidance, no mention of when to prefer get_subscriber, and no exclusions.

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