Remove Inbox Thread Label

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

Annotations already declare destructiveHint=false, and the description corroborates and enriches this by stating the label itself is kept and remains on every other thread, plus an idempotency note and the return shape. It discloses preservation semantics that go well beyond the annotation set.

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?

Bold-labeled sections front-load purpose, exclusions, return value, and usage in a scannable order. Every line carries information; nothing is redundant padding.

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?

Despite no output schema, the description summarizes the return value ('labels left on the thread after the change') and covers purpose, exclusions, idempotency, and ID sourcing. Nothing an agent needs to call it correctly is missing.

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%, so the baseline is 3, but the description adds real value by telling the agent where to source each ID (threadId from list-inbox-threads, labelId from the thread's labels or list-inbox-labels). It does not restate the inboxId/email-address nuance already in the schema.

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 ('Take one label off one thread in a Resend inbox') and explicitly scopes it against the sibling remove-inbox-label. An agent can distinguish it from add-inbox-thread-labels and set-inbox-thread-labels without opening any schema.

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?

Includes an explicit 'When to use' (user asks to untag/unlabel a thread), a 'NOT for' exclusion naming the alternative tool, and idempotency guidance ('Removing a label the thread does not carry changes nothing'). This covers when, when-not, and alternatives.

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