Update Topic

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

With no annotations, the description carries the full burden. It discloses a key behavioral constraint (defaultSubscription cannot be modified) but omits other behavioral details such as error handling, permissions, idempotency, or response format. The provided note adds value but is not comprehensive.

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?

The description is two sentences, with the primary action in the first sentence and a concise note in the second. No redundant information or filler; every word earns its place.

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?

For a simple update tool with three parameters and no output schema, the description covers the essential purpose and a critical constraint. It does not mention return values or error behavior, but given the simplicity and schema availability, it is sufficiently complete for an agent to use it correctly.

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?

The input schema already describes all three parameters, covering 100% of them. The description adds meaningful constraint information about a field not present in the schema (defaultSubscription), clarifying that this field is not updatable. This goes beyond the schema's basic descriptions.

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 clearly states the verb ('Update') and resource ('existing topic'), making it immediately identifiable among sibling update tools. The specific mention of 'in Resend' adds context, and the note about defaultSubscription further defines the operation's scope.

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?

It is clear this tool is for updating an existing topic, not creating one. The note about defaultSubscription provides a meaningful 'when not to' guideline for a specific field, though it does not explicitly name alternatives or broader usage scenarios.

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