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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description reveals important behavioral details: invalid drafts with unfilled placeholders or broken links are refused, the operation is free, and the 'act' scope is required. This gives the agent meaningful expectations about validation and auth without relying on the 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?

Two tightly packed sentences front-load the core operation and immediately follow with failure behavior and prerequisites. No wasted words; every clause adds operational relevance.

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 mutation tool with a nested object parameter and no output schema, the description covers purpose, lifecycle timing, validation, cost, and scope. It does not mention the draft_fence parameter, but the schema's own description for that parameter provides the necessary guidance, so the overall tool definition is sufficiently complete.

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?

With 100% schema description coverage, the baseline is 3. The tool description adds value by explaining that draft_content must be a valid marketing draft body and by stating the validation rule around placeholders and broken links, which clarifies acceptable inputs beyond the schema's basic string constraints.

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 states a specific action—'Replace a pending growth move's marketing draft body before shipping'—with a clear verb (replace), resource (marketing draft body), and lifecycle context (pending, before shipping). This differentiates it from siblings like redraft_output or ship_move without needing to inspect either schema.

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 clear context for when to use the tool—only for pending moves before shipping—and states that invalid drafts are refused rather than saved. It does not explicitly name sibling alternatives or exclusion conditions, so it stops short of full when/when-not guidance.

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