read_email

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

No annotations are provided, so the description carries full burden. It states the tool reads email bodies but doesn't disclose behavioral traits like whether it requires specific permissions, if it's a read-only operation, what happens if IDs are invalid, or if there are rate limits. The description is minimal and lacks essential operational context for a tool that accesses email data.

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, efficient sentence that front-loads the core purpose and includes necessary contextual information about parameter sources. Every word serves a purpose with zero waste, making it appropriately sized for this simple tool.

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 low complexity (2 required parameters, no output schema, no annotations), the description is adequate but minimal. It covers the basic purpose and parameter sources but lacks information about return values, error conditions, or behavioral constraints. For a read operation without annotations, more context about what 'read' entails would be beneficial.

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%, with both parameters clearly documented in the schema. The description adds marginal value by reinforcing that both parameters come from list_inbox and search_emails, but doesn't provide additional semantic context beyond what's already in the schema descriptions. This meets the baseline for 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 verb 'read' and the resource 'full body of an email', making the purpose specific and understandable. It distinguishes from siblings by specifying it's for reading individual emails rather than listing/searching (list_inbox, search_emails) or sending (send_email). However, it doesn't explicitly contrast with all siblings in a single statement.

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: after obtaining messageId and folderId from list_inbox or search_emails. This implicitly distinguishes it from send_email and gives prerequisites. However, it doesn't explicitly state when NOT to use it or name alternatives for similar tasks.

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