Add spam whitelist entry

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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond them: a 409 conflict when the entry already exists, case-insensitive duplicate matching, and the account-wide blast radius of the change. It stops short of 5 because nothing is said about rate limits or the success response.

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?

Three tight sentences: what it does and its scope, then the error/duplicate behavior, then the domain-vs-list constraint. No filler, and the highest-value information (effect and scope) is front-loaded.

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 two-parameter mutation with full schema coverage and annotations carrying the safety profile, the description covers effect, duplicate handling, precondition, and scope. It could still say what a success returns or when the whitelist takes effect, but nothing needed to invoke it correctly is missing.

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 100%, so baseline is 3, but the description resolves the non-obvious ambiguity between the required 'domain' (must be owned) and the account-wide scope of the list itself, plus restates that 'entry' accepts wildcard patterns. That is real added meaning over the schema text.

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 (adds) and resource (spam whitelist entry) plus the concrete effect: sender mail bypasses spam filtering account-wide. The verb+noun naming plus the sibling set (add/remove/list whitelist vs. blacklist) makes it trivially distinguishable from remove_spam_whitelist_entry and add_spam_blacklist_entry.

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?

Gives clear context (account-wide whitelist affecting every domain) and a real prerequisite: the domain argument must be a domain you own even though the list is account-wide. It never explicitly names an alternative or a when-not-to-use case, so it stops short of a 5.

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