read_email

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

Annotations already mark the tool as readOnlyHint=true, so the description's disclosure of read behavior is not additional. However, the description adds significant value by detailing what the tool returns (cleaned body, sanitization report, classification, extracted data), which goes well beyond the annotations. No contradiction with annotations.

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?

Two sentences that are entirely informative. The first sentence enumerates the return values, the second provides the usage cue. No filler, redundant phrases, or unnecessary elaboration.

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 complexity (single parameter, no output schema), the description is nearly complete: it specifies what the tool does, what it returns, and when to call it. It could be slightly more complete by mentioning if the cleaned body includes attachments or by clarifying the 'sanitization report' and 'classification' in more detail, but for a single-param tool this is very strong.

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%, so the baseline is 3. The description adds context by explaining the type of usage (reading a message, getting extraction), but does not add new semantic details about the message_id parameter beyond what the schema already provides (type, format, and source hint). A small lift over baseline due to usage context.

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 resource 'one email', explicitly listing what the result includes (body, sanitization report, classification, extracted data). It distinguishes itself from siblings like list_inbox and wait_for_email by specifying this is for reading a specific message in full.

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 includes the explicit usage trigger 'Call this when you need the content or extraction of a specific message.' This provides clear context for when to use it. However, it does not mention when not to use it (e.g., if only basic metadata is needed, list_inbox might be more efficient) or explicitly name alternatives.

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