imap_add_spam_domain

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explains the effect of flagging emails as spam, which adds useful context, but it does not mention duplicate behavior, whether existing emails are affected, or whether the addition is persistent.

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?

The description is two short sentences with no filler. The primary action is front-loaded, followed immediately by the behavioral consequence, making it easy for an agent to parse quickly.

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 single-parameter, no-output-schema tool, the description covers the essential operation and effect. It is slightly light on edge-case behavior such as duplicates or relationship to whitelisting, but it is complete enough for a straightforward list-add mutation.

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?

The schema covers the single parameter fully with a type and example, so baseline is 3. The description does not add additional parameter-level meaning beyond restating 'domain', but this is acceptable given the high schema coverage.

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 clearly states the action: adding a domain to a custom spam list, and explains the practical consequence that emails from that domain will be flagged as spam. This distinguishes it from sibling tools like imap_remove_spam_domain and imap_add_whitelist_domain.

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?

The description implies the tool is used when a domain should be treated as spam, but it does not explicitly mention alternatives or conditions. No guidance is given about when to prefer this over imap_add_whitelist_domain or how it relates to imap_check_spam.

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