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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description's one contribution beyond structured data is the sort order (most recently created first), which the schema does not state; it says nothing about pagination limits or the return shape.

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 filler and no repetition of the title. It is efficient, though arguably too terse for a tool whose filter semantics carry real behavioral weight.

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 explained, and annotations carry the safety profile. However, for a 4-parameter paginated listing tool with only half the parameters documented, the description leaves the limit parameter and pagination workflow entirely unexplained.

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 coverage is only 50%, and the description adds nothing about limit, state, or cursor semantics. 'An inbox's drafts' loosely implies inbox_id filtering, but the undocumented limit parameter receives no explanation in either place, so the description fails to compensate for the coverage gap.

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?

States a specific verb (list) and resource (an inbox's drafts) plus an ordering guarantee. It is distinguishable from singular siblings like get_draft and from list_messages/list_sent, though it never explicitly contrasts itself with them.

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?

Gives no when-to-use context: no mention of the state filter for choosing between editable and submitted drafts, no note about paginating via cursor, and no routing to related tools such as get_draft or list_trash. The agent must infer usage entirely from the schema.

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