Manage suppression

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

Adds substantial context beyond the annotations: the list is honored by every outward tool, cannot be bypassed from a tool call, is free and local, and that add is idempotent while remove needs the exact value. The annotation idempotentHint=false is a coarse tool-level hint for a four-action tool and is consistent with the non-idempotent-sensitive actions, so there is no true conflict, but the mismatch on 'add' is worth noting.

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?

Five compact sentences, front-loaded with the core purpose and the suppression semantics that matter most. Slightly telegraphic in the closing sentence but nothing is wasted.

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 6-parameter, 0%-coverage, no-output-schema tool, the description covers the domain semantics well but leaves pagination (limit/cursor) and the check/list response shape undocumented, so an agent calling list or check lacks full guidance.

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 0% across 6 parameters, so the description must carry the burden. It clarifies the email/domain value types and per-action semantics for add (idempotent) and remove (exact value required), but says nothing about limit, cursor, or reason, and does not explain what list and check return.

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?

The description names a specific resource (the do-not-contact list of emails and domains) and a specific capability set (maintain + check values against it). No sibling tool (search, enrich, verify, campaign push) overlaps this resource, so the agent can route unambiguously.

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?

It gives concrete triggers: 'when a prospect opts out, bounces, or asks not to be contacted.' That is clear usage context, though it does not explicitly state when NOT to use it or name an alternative path for checking suppression status.

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