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

Annotations already mark destructiveHint=true, but the description adds specific behavioral detail: the address 'will receive nothing further, neither campaigns nor transactional emails.' It also implies permanence ('further') and identifies the manual-suppression context. This is meaningful context beyond the annotations, though it doesn't mention reversibility or permissions.

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 sentences, no filler. The core action is front-loaded, the consequence follows, and the use case closes it. Every word earns its place.

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 tool with 2 parameters, no output schema, and 0% schema description coverage, the description needs to explain the parameters for safe invocation. It provides the purpose and use case but omits meaning of 'reason' and any mention of optionality. An agent could guess why to call it but not confidently choose the correct reason enum.

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 0%, but the description does not explain either parameter. It only says 'an address' (presumably email) and never discusses the 'reason' field, its enum values, or the fact that only email is required. The description fails to compensate for the schema's lack of documentation.

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?

Description states a specific verb+resource ('Adds an address to the workspace's suppression list') and the clear effect (receives nothing further). This is unambiguous and easily distinguished from siblings like add_subscriber or send_campaign, even without naming them.

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?

Provides an explicit use case: 'Use when someone requests no further contact outside the unsubscribe link.' This tells the agent when to apply the tool, but it doesn't mention alternatives or exclusions, so it falls just short of full routing guidance.

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