Read multiple emails

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description does not need to repeat those. It adds value by disclosing a bounded request (limit of 50) and 'per-ID errors', indicating partial failure handling. This goes beyond the annotations and helps the agent predict behavior.

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 a single, compact sentence: 'Read up to 50 emails in one bounded request, with per-ID errors.' It front-loads the core action and includes key constraints efficiently without any filler. Every phrase contributes to understanding.

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 existence of an output schema and thorough parameter documentation, the description covers the essential context: it explains the batch nature, the limit, and error handling. It does not mention what happens if more than 50 IDs are supplied, but the schema's maxItems=50 covers validation. Overall, it's sufficient for an agent to call 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% with rich parameter descriptions (e.g., ids 'Envelope IDs returned by search, recent, or thread tools' and view enum with meanings). The tool description does not add meaning beyond the schema, which already explains both parameters adequately. Base score of 3 is appropriate.

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 states a specific verb ('Read'), a resource ('emails'), and a distinctive scope ('up to 50', 'one bounded request'), which clearly separates it from siblings like search_emails (searching) or list_recent (listing). It also mentions 'per-ID errors', adding specificity. This is a clear, non-tautological purpose.

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 a batch operation but does not explicitly state when to use this over get_email (single) or search_emails. It mentions 'bounded request' but lacks explicit guidance on selecting this tool versus alternatives. An agent could infer from the name and 'multiple emails', but explicit when-to-use instructions are absent.

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