Get message text

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

With no annotations, the description fully discloses important behavioral traits: it strips quoted reply history, applies a length cap, returns content inside an untrusted-content marker, and specifically explains the null-return condition when the body index is missing. It even provides the reasoning about Apple's per-mailbox row numbers, giving deeper insight into the tool's limitations.

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 compact and well-structured: it leads with the core function, then a security note, then a limitation with a clear reason. Every sentence adds unique value, and there is no filler or repetition of schema details.

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 one-parameter tool with no output schema, the description addresses all critical aspects: what it returns (readable text), how it transforms input (removes quotes, caps length), how to interpret output (untrusted marker), and when it might fail (missing index). It is fully self-contained and leaves no major gaps for an AI agent.

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 already provides a rich description for the sole 'key' parameter (opaque, stable, rejects Apple's row numbers). The tool description adds context by explaining why row numbers fail (per-mailbox) and tying the parameter to the required body index, enhancing the schema's semantics without redundancy.

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 tool gets 'the readable text of one message' with specific transformations (removes quoted reply history, length cap). This distinguishes it from siblings like get_email_links and get_email_attachment, making its purpose unmistakable.

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 sets clear context for when to use the tool (to retrieve readable message text) and explicitly warns about a prerequisite (published body index) that gates usage. It does not explicitly name alternative tools, but the sibling names and purpose make the intended use clear without ambiguity.

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