list_emails_from_domain

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

With no annotations provided, the description carries full burden and does well by disclosing key behaviors: it describes the return format (array of objects with id, subject, from, date), sorting order (newest-first), and how to use the returned id with another tool (fetch_email_content). It doesn't mention rate limits, authentication needs, or pagination behavior, but covers essential operational context.

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 perfectly front-loaded with the core purpose in the first sentence, followed by return format and usage guidance. Every sentence earns its place: the first explains what the tool does, the second describes output structure, and the third provides critical follow-up action guidance. Zero wasted words.

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 read-only listing tool with no annotations and no output schema, the description provides excellent coverage: purpose, parameters (via schema), return format, sorting, and tool chaining guidance. The only minor gap is lack of explicit mention about whether this is a search across all mailboxes or just the specified one, but the schema clarifies the mailbox parameter default.

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 the schema already fully documents both parameters. The description adds the example 'you.com' which reinforces the domain parameter format, but doesn't provide additional semantic context beyond what's in the schema. This meets the baseline expectation when schema coverage is complete.

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 verb 'List' and resource 'emails from a specific domain', with a concrete example ('you.com' finds all emails from @you.com senders). It explicitly distinguishes from siblings like list_emails_from_sender by focusing on domain-level filtering rather than individual sender addresses.

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 provides clear context for when to use this tool (searching by domain) and implicitly distinguishes it from time-based siblings (list_emails_24h, list_emails_7days, etc.) by not mentioning time constraints. However, it doesn't explicitly state when NOT to use it or name specific alternatives beyond the implied differentiation.

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