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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds one genuinely useful trait beyond them — the returned text is 'sanitized' and 'full' — but says nothing about truncation, size limits, or failure modes when the id is stale or invalid.

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?

One sentence, front-loaded with the return value and ending with the input constraint. Nothing is redundant or padded.

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 1-parameter read tool with rich annotations and no output schema, this is minimally sufficient. But with close siblings like get_message, get_thread, and get_attachment, the absence of any statement about how this differs is a real completeness gap.

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% and the single id parameter is already documented as 'Document id from search'. The description restates the same origin of the id without adding format, validation, or scope details, so baseline 3 applies.

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 and resource: returns the full sanitized text of one email, identified by an id. It also scopes the input source ('by the id returned from `search`'). However, it never distinguishes itself from the sibling get_message, which an agent would reasonably assume does the same thing.

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?

Usage is implied rather than stated: the mention that the id comes from `search` tells the agent this is a follow-up call after a search. There is no explicit when-to-use/when-not guidance and no mention of when get_message or get_thread would be preferred instead.

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