List all subscribers.

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond that — no mention of pagination behavior, default page size, result ordering, or account scoping, all of which are relevant for a listing call.

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?

A single front-loaded clause with zero waste, which is good structurally. But it is under-specified rather than genuinely concise — the brevity comes from omitting information rather than from tight writing.

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 no-required-param list tool with a fully documented schema and a complete annotation set, the description is minimally viable. It does not need to explain return values (no output schema exists, but list semantics are conventional), yet it omits any note on filtering combinations or pagination that would help an agent call it correctly.

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%, with all five parameters (page, per_page, status, account, segment_id) fully documented including enum semantics. The description contributes no additional parameter meaning, so the baseline of 3 applies when the schema does all the work.

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?

Tautological: description restates name/title.

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?

No guidance on when to use this tool versus alternatives such as get_subscriber (single) or the segment/workflow listers. The agent must infer usage from the name alone; nothing is said about preconditions, pagination strategy, or when filtering by segment_id/status is warranted.

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