list_agents

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

Annotations provide a title ('List All Agents') but no hints like readOnly or destructive. The description adds value by implying this is a read operation (listing) and suggesting it's used in conjunction with creation and interaction tools, but doesn't disclose behavioral traits such as pagination, rate limits, or auth requirements. With no annotations, the description carries some burden but leaves gaps.

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: the first states the purpose clearly, and the second provides usage guidelines efficiently. Every sentence earns its place with no wasted words, making it appropriately sized and front-loaded.

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's low complexity (one optional parameter), 100% schema coverage, and the presence of an output schema (which handles return values), the description is mostly complete. It covers purpose and usage well but could improve by adding more behavioral context (e.g., response format or limitations), keeping it from a perfect score.

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 100% for the single parameter 'filter', documented as 'Optional filter to search for specific agents'. The description adds no additional parameter information beyond what the schema provides, so it meets the baseline of 3 for high coverage without 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 verb ('List') and resource ('all available agents in the Letta system'), making the purpose specific and unambiguous. It distinguishes this tool from siblings like 'get_agent_summary' (for details) and 'prompt_agent' (to interact), avoiding tautology.

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 provides usage context by naming three sibling tools as alternatives for different purposes: 'create_agent' to add new ones, 'get_agent_summary' for details, and 'prompt_agent' to interact. This gives clear guidance on when to use this tool versus others.

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