Add Spam Whitelist Entry

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

Annotations already declare a non-read-only, non-idempotent, non-destructive mutation, and the description adds genuinely new behavior: a 409 response when the entry already exists, case-insensitive matching, and the fact that whitelists are shared across all domains. It does not describe auth requirements or the response payload, but the output schema covers the latter.

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?

Four tight clauses, front-loaded with purpose followed by syntax, error behavior, and scope. Each sentence carries distinct information, with only minor overlap between the wildcard note and the schema.

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?

An output schema exists, so return values need no explanation. For a two-parameter mutation the description covers purpose, accepted syntax, duplicate handling, and scope semantics, leaving nothing an agent needs in order to call it correctly.

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 coverage is already 100%, so the baseline is 3; the description earns above that by explaining that wildcards like `*@trusted.com` are valid and that matching is case-insensitive. The note that sender lists are shared across all domains is especially valuable because it clarifies that `domain` does not scope the entry itself.

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?

"Adds an entry to the spam whitelist; whitelisted senders bypass spam filtering" gives a concrete verb, resource, and the effect of the operation. The name alone separates it from add_spam_blacklist_entry and remove_spam_whitelist_entry, but the description never states those distinctions explicitly, so it falls short of 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?

Usage context is implied by the tool name and reinforced by notes on wildcard support and the account-wide sharing of sender lists, which tells the agent the entry is not scoped to one domain. However, there is no explicit when-to-use or when-not routing against add_spam_blacklist_entry, update_spam_settings, or a prerequisite of checking get_spam_whitelist first.

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