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

Annotations already declare this is a write operation (readOnlyHint=false), non-destructive, and closed-world, so the safety profile is covered without description help. The description adds the type-dependent field requirements, but says nothing about permissions, limits on number of messages, or what is returned on success.

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 compact sentences, front-loaded with the purpose and then the conditional field rules. No wasted words, though the second sentence duplicates what the schema already states about type-dependent requirements.

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?

With no output schema, the description doesn't hint at what a successful add returns. It also covers only three of the nine enumerated types (ai, redirect, email) and leaves intercom, follow_up*, and escalate behavior unexplained, which is a meaningful gap for an agent choosing 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 100%, so every parameter is already documented in the schema (including the required-when-type conditions). The description largely restates those same type-to-field mappings and adds only the 'ai is default' detail, so the baseline of 3 is appropriate.

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 gives a specific verb+resource (add a suggested message) and parenthetically defines what the resource is ('a clickable prompt shown to visitors'), which an agent can't get from the name alone. It doesn't explicitly name or contrast with the sibling tools (list_suggested_messages, update_suggested_message, remove_suggested_message), but the create semantics are unambiguous.

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?

It provides conditional guidance keyed on the 'type' value (ai vs redirect/email), which is genuinely useful for filling the form. However, it gives no when-to-use/when-not guidance relative to siblings and no prerequisites or conditions under which adding a suggested message is appropriate.

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