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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's job is to add domain semantics — and it does: a blocked domain cascades to all subdomains, and already-emailed domains are omitted. What it does not describe is the shape of the returned list.

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?

Three short sentences, purpose front-loaded, and each subsequent sentence earns its place by defining cascade behavior and an exclusion rule. No filler.

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 one-parameter read tool with no output schema, the description conveys what the result conceptually contains and what it deliberately omits. Only the concrete return format (list of strings vs. objects) is left unstated, which is a minor gap.

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% and the workspaceId description already explains how to discover valid values via get_status. The description adds nothing about the parameter, so baseline 3 is correct.

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?

Names a specific resource ('the domains the person has blocked for this site') and the scope of that resource. It is implicitly the read counterpart to block_domains/unblock_domains, but it never contrasts itself with those siblings by name.

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?

Usage is only implied — an agent would infer 'check this before blocking/unblocking.' The description does clarify a boundary condition (already-emailed sites are excluded), which is useful, but it gives no explicit when-to-use statement or alternative routing.

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