List messages

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

The description adds behavioral details beyond the annotations (readOnlyHint, openWorldHint) by specifying cursor-paginated, newest-first ordering, and the scope requirement, enhancing transparency about its operation.

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 extremely concise, using two clear sentences that front-load the key information (paginated list, ordering, scope) without any unnecessary words.

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?

Given the tool has three optional parameters and no output schema, the description adequately covers the purpose and prerequisites but could be more complete by hinting at the return format or typical use cases, such as filtering by status.

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 67% (two of three parameters have descriptions). The tool description does not provide additional parameter details beyond what the schema already offers, so it meets the baseline without adding extra value.

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 tool lists messages with cursor-based pagination and newest-first ordering, and it distinguishes from sibling tools like hellio_get_message by focusing on a list, but it does not explicitly name alternatives.

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 mentions the required 'reports' scope, which is a prerequisite, but it does not provide guidance on when to use this tool versus alternatives like hellio_get_message or hellio_list_campaigns, nor does it explain when not to use it.

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