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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds only 'saved', which weakly implies sent (not draft) messages, and says nothing about pagination behavior or result ordering beyond what structured fields provide.

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?

A single front-loaded sentence with no wasted words. It is efficient, though it largely echoes the title 'Find outgoing emails', so the marginal informational value is small.

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?

An output schema exists, so return values need not be described, and 85% of the 13 parameters are documented in the schema. However, for a 13-parameter search tool the description is thin: it omits any note about the required inbox_id, the cursor-based pagination loop, or how filter groups combine.

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 85%, so the parameters (query, subject, from, recipient, label groups, cursor, ordering) are already well documented in the schema. The description adds no syntax, defaults, or interaction rules beyond 'combined search and filters', so the 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 clear verb and resource ('Find saved outgoing emails') and signals the tool is a filtered list operation. It does not explicitly distinguish itself from close siblings like list_messages or get_sent_message, but the 'outgoing/sent' scoping is unambiguous enough to select it correctly.

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?

There is no when-to-use guidance, no exclusions, and no mention of alternatives such as list_messages (incoming) or get_sent_message (single message). An agent must infer from the name alone which sibling applies.

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