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

With no annotations, the description carries the behavioral burden well: it discloses the effect is permanent ('ever'), that the operation is idempotent, that no other credential is required, and that scope is limited to the host that received the message. It omits what happens with an invalid/expired token and what the call returns.

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, front-loaded with the effect and followed by the parameter provenance and the idempotency/auth note. No sentence is redundant or padding.

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 mutation tool with no annotations and no output schema, the description covers effect, permanence, idempotency, and credential sourcing. The only gap is the return value / error behavior, which the agent could reasonably want before calling.

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%, so the description must compensate, and it does: it explains where the token comes from, that it is the last path segment of the opt-out link, and why no other credential is needed. Only the 16–64 char length constraint is left to the schema, which is a minor residual.

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 effect ('Stop AgentsJunction from ever messaging the host that received an outreach message'), naming the exact scope of the action. It is unmistakably distinct from every sibling tool (none of which concern outreach or opt-outs).

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?

Tells the agent exactly when and how to use it: take the token from the opt-out link in the message, specifically the last path segment. It does not discuss failure modes or when-not-to-use, but no plausible alternative tool exists, so the guidance is effectively complete.

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