List Topics

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

Annotations already declare readOnlyHint=true, and the description's 'List all topics' is consistent. It adds context about returning topic IDs for downstream use but does not disclose behavior like pagination or response format. With annotations covering the safety profile, the additional context is moderate.

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 no redundant information. It front-loads the action and resource, then adds a brief use case.

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 parameterless list tool, the description covers what it does and why it's useful. It doesn't describe the output shape, but no output schema exists and the 'topic IDs' hint provides some guidance. Given the low complexity, this is adequately 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?

The input schema has zero parameters, so the description does not need to detail parameter semantics. It mentions 'all topics' implying no filtering, which adds slight value over the empty schema. Baseline for 0 params is 4.

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 uses the verb 'List' with the specific resource 'topics from Resend', clearly distinguishing this tool from list-contact-topics in the siblings. It also states the purpose of retrieving topic IDs for use by other tools.

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?

The description explicitly states a use case: 'useful for getting topic IDs to use with other tools like send-email.' This provides clear context for when to use it, though it doesn't mention exclusions or alternative tools.

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