Get Emails

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

Annotations already declare readOnlyHint and openWorldHint. The description adds valuable behavioral details: explains the semantics of id vs messageId, the effect of summaryOnly, and pagination mechanics, going beyond the annotations without contradiction.

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 concise sentences, each serving a purpose: purpose statement, fields overview, id clarification, pagination/summaryOnly guidance. Front-loaded with the primary action, no 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?

Given the tool's complexity (4 parameters, output schema exists), the description covers all needed aspects: pagination, parameter options, field distinctions, and references to complementary tools. Agents have sufficient info to select and invoke 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 100%, so baseline is 3. However, the description adds context: explains id as per-folder UID vs stable messageId, and summaryOnly for lean payloads. This meaningfully supplements the schema.

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 and resource: 'Fetch a page of emails from a folder.' It distinguishes itself from siblings like get_email_by_id and search_emails by specifying it returns summary fields and supports pagination, making its purpose unambiguous.

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?

Provides clear context for use: pagination via nextCursor, summaryOnly for lean listing, and reference to get_email_by_id for full content. While it doesn't explicitly exclude use cases, the guidance on pagination and summarization is sufficient.

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