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

Annotations already declare readOnlyHint=false, openWorldHint=false, and destructiveHint=true, so the safety profile is covered structurally. The description adds no behavioral context beyond that: it does not explain what gets overwritten, whether permissions are needed, or whether the label replaces an existing value.

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?

A single front-loaded sentence with no filler or repetition. Every word contributes to stating the action, target, and scope.

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 4 parameters, 0% schema coverage, and no parameter descriptions, the definition is too sparse. An output schema and annotations exist, but the description still omits usage conditions and the meaning of three of four parameters.

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% for 4 parameters. The description names the target field ('display label') but does not document the other three parameters (owner_ref, fb_user_label, connection_context), so it fails to compensate for the schema gap.

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 verb ('Set') and resource ('display label') with scope ('one FB user connection'), so the purpose is clear. It does not distinguish this from sibling tools such as fb_users_update_permissions or fb_users_list, which prevents a 5.

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?

No guidance is given about when to use this tool versus alternatives, nor are prerequisites or confirmation requirements mentioned. The scope phrase 'one FB user connection' hints at usage but does not constitute explicit guidance.

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