mail_change_settings

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

Annotations already declare this is a non-read-only, non-destructive, closed-world mutation. The description usefully adds the '-1 = do not change' convention for the defaults, which tells the agent that omitted optional fields leave settings untouched. It does not describe permissions, reversibility, or side effects beyond that.

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?

Front-loaded with the purpose, then a compact per-argument list with no wasted filler. The args block is somewhat duplicative of the named schema fields, but necessary since schema coverage is 0%.

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 not be described. All five parameters are addressed and the required domain/mailbox pair is identifiable, leaving only sibling routing as a gap.

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%, so the description carries the full parameter burden, and it does so well: it maps spam_filter_status (1/0/-1), spam_filter (-1 = no change), and forward_mail_status (no_forward/forward/forward_and_delete) to concrete meanings. domain and mailbox are only trivially glossed, keeping it from a 5.

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 opening states a clear verb+resource: modifying mailbox settings, specifically the spam filter and forwarding. It does not, however, distinguish this tool from siblings such as mail_forward_add, mail_forward_delete, or mail_set_domain_mail, which overlap in 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?

There is no guidance on when to use this tool versus the dedicated forwarding tools (mail_forward_add/delete) that are siblings, nor any prerequisites or exclusions. The agent must infer context entirely.

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