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

Annotations already declare readOnlyHint=false, destructiveHint=true, and openWorldHint=false, so the mutation/risk profile is covered structurally. The description adds no behavioral context beyond that – it doesn't say what toggling these flags actually does, whether the change is reversible, or what permissions are required.

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 terse sentence with the verb and the affected fields front-loaded; nothing is wasted. It is efficient, though the extreme brevity is what creates the informational gaps elsewhere.

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 destructive, permission-altering mutation with a 0%-documented schema, the description is too thin. An output schema exists so return values need not be explained, but the agent still lacks any sense of the effect or scope of these flag changes.

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% across 5 parameters, so the description must carry the burden. It names three of the five parameters but provides no meaning for any of them (e.g. what allow_decision routing controls), and leaves ad_account_id and connection_context entirely unaddressed.

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 ('Update') and resource ('routing flags'), and names the three flags it toggles (allow_create, allow_pull, allow_decision). It does not distinguish itself from related siblings like fb_users_update_permissions or fb_users_refresh_routing, so an agent could confuse the scope.

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 on when to use this tool versus alternatives, no prerequisites, and no exclusions. The presence of multiple similarly-named permission/routing tools (fb_users_update_permissions, fb_users_refresh_routing) makes this absence more costly.

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