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

With no annotations, the description carries the full burden; it usefully discloses the effect (campaigns skip the address) and the default blocking scope. It omits key behavioral facts: whether suppression is reversible, what happens if the address is already suppressed, whether a project context is required, and any permission requirements.

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 tight sentences, front-loaded with the action and effect, then the parameter default. No filler or redundancy.

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?

A six-parameter mutation tool with no annotations and no output schema needs more: project targeting, the reason enum's meaning, and duplicate/already-suppressed behavior are unaddressed. The category explanation is good but covers only one of six parameters.

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 50%; the description adds meaning only for category (default 'all' vs. a single category key), largely echoing the schema's own description. The other four non-required parameters (note, reason, project_id, project_slug) get no mention, and the ambiguity of choosing between project_id and project_slug is unresolved.

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 (suppress an email address) plus the downstream effect (lifecycle email campaigns skip it), which is more than a restatement of the name. It does not explicitly contrast with the sibling unsuppress_email_recipient or list_email_suppressions, so differentiation is left to the 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?

Explains the category default ('all' blocks everything) and when to pass a specific key instead, and routes to list_email_categories for discovery. However, it gives no guidance on when to use this tool versus unsuppress_email_recipient or the deliverability tools, and no prerequisites (e.g. project scoping) are stated.

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