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

Annotations only state readOnlyHint=false and openWorldHint=true. The description adds substantial behavioral context beyond this: it creates a draft (not sent), sends via Gmail, requires user Gmail connection, and that campaigns are topped up not replaced. This is useful non-destructive and external-effect context not present in annotations.

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?

The description is front-loaded with the core purpose in the first sentence, then organized as a numbered flow that earns its place by clarifying the tool's role. Despite being longer than typical descriptions, every sentence contributes necessary context (steps, prerequisites, continuation behavior) without fluff.

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?

The description provides a complete workflow, prerequisite, and continuation guidance, making it easy for an agent to sequence this tool correctly. It lacks an explicit statement of the return value (e.g., campaign ID), but the workflow implies the next steps (e.g., outreach_add_contacts) and the lack of an output schema makes this 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?

The input schema descriptions already cover all three parameters (goal, name, your_domain) with examples, giving 100% schema coverage. The description does not add additional parameter-level meaning, so the baseline of 3 applies.

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 opens with 'Create a draft link-building outreach campaign (sends via the user's connected Gmail)', providing a specific verb and resource. It clearly distinguishes this tool from siblings by noting it creates a draft (not launch) and is part of a larger outreach flow.

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?

The description provides an explicit 8-step outreach flow, placing this tool at step 5. It directly tells when to use the alternative path: 'To CONTINUE an existing campaign rather than start a new one, begin at outreach_suggest_prospects instead of step 1 — campaigns are topped up, not replaced.' It also states the Gmail connection prerequisite.

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