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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds scope details — default status of active, the meaning of 'active' and 'orphans', and inclusion of mailing counts and custom fields — that go beyond the annotations.

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?

Front-loaded with the resource and returned fields, then status semantics, then filters. The trailing 'GET /members.' is minor filler but the rest is dense with no wasted sentences.

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?

No output schema exists, so the description's enumeration of returned fields (name, email, language, consent type, mailing counts, custom fields) is essential and present. Defaults and edge-case statuses are covered, leaving nothing critical unclear for calling the tool.

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 coverage is 100%, so baseline is 3, but the description adds real semantics: it clarifies what status=active vs orphans means and that joined/updated filters apply. Sort and pagination details are left to the schema.

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?

States a specific verb and resource (list subscribed contacts/members) and enumerates the fields returned, so the agent knows exactly what it gets. It also differentiates from siblings by noting bounced and unsubscribed members have their own tools.

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?

Explains the status modes and their defaults, date filtering, and points away from this tool for bounced/unsubscribed contacts. It doesn't explicitly compare against get_member or list_group_members, but the context is clear.

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