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

The readOnlyHint annotation already establishes this is a safe read, so the description does not need to restate safety. It adds the endpoint mapping but says nothing about pagination behavior, ordering of drafts, or whether drafts from other users are included.

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 short sentences with the operation front-loaded and no wasted prose. The endpoint citation is marginally redundant given the tool name but is compact and useful for disambiguation.

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?

A simple read-only list endpoint with full schema coverage and no output schema, so the description does not need to explain return values. Only the absence of any when-to-use framing and any note on draft ordering/paging limits keeps it from being fully complete.

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 id, limit, and until are already documented in the schema, including the cursor semantics of 'until'. The description adds no parameter-level meaning beyond what the schema provides, which is the baseline-3 case.

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+resource ('List draft messages on a conversation') and appends the underlying endpoint, which pins down exactly what is returned. It is naturally distinct from the sibling list tools (messages, comments, posts), though it never names an alternative explicitly.

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 guidance on when to call this versus missive_list_conversation_messages, missive_list_conversation_comments, or missive_create_draft. The agent must infer usage purely from the resource noun.

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