Get Inbox Draft

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds meaningful context beyond that by enumerating what the body contains (recipients, subject, html, text, attached files, and reply thread/message) and disclosing it returns the body unlike the thread sibling. No auth or rate-limit notes, but for a read operation against a fully-covered safety profile this is substantial.

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?

Three tight sentences with zero filler: the return scope is front-loaded, the sibling contrast follows, and the workflow pointer closes. Every sentence carries distinct information.

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?

No output schema exists, so the description must carry return-value meaning, and it does by enumerating the returned fields. With 2/2 params documented at 100% coverage and annotations covering safety, the only small gap is the absence of any error/not-found behavior for an invalid ID.

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 100% and both parameters are schema-documented, so the baseline is 3. The description only reinforces the draftId origin ('from list-inbox-drafts'), adding no new syntax or format meaning beyond the schema, and says nothing extra about inboxId.

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 and resource ('Get a draft by ID from a Resend inbox') plus the scope of what is returned. It explicitly distinguishes itself from the sibling get-inbox-thread ('lists a whole conversation without the bodies'), so an agent can route between them without opening schemas.

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?

Names the workflow position explicitly: 'Use this to read a draft back before send-inbox-draft puts it in the mail.' It also tells the agent where the required ID comes from ('Get the draft ID from list-inbox-drafts') and contrasts the read shape against list-inbox-threads/get-inbox-thread.

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