create_memory_block

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

Annotations only provide a title, so the description carries the full burden of behavioral disclosure. It states this is a creation operation (implying mutation) and mentions common labels, but doesn't address permissions, error conditions, rate limits, or what happens when creating duplicate blocks. It adds some context but lacks comprehensive behavioral details.

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 perfectly concise with two sentences that each earn their place: the first states the core purpose, the second provides usage guidance and sibling differentiation. No wasted words, and information is front-loaded appropriately.

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 that an output schema exists (so return values are documented elsewhere), the description provides good context for a creation tool. It covers purpose, usage guidelines, and parameter hints, though could benefit from more behavioral details about the creation operation's implications in the system.

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%, so the schema already documents all 5 parameters thoroughly. The description adds minimal value beyond the schema by mentioning common label examples ('persona', 'human', 'system'), which slightly enhances understanding of the 'label' parameter. This meets the baseline for high schema coverage.

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 specific action ('Create a new memory block') and resource ('in the Letta system'), distinguishing it from siblings like 'update_memory_block' (modification) and 'attach_memory_block' (linking). It provides concrete examples of common labels ('persona', 'human', 'system') to clarify the tool's domain.

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 when-to-use guidance by naming alternatives: 'Use attach_memory_block to link to agents, or update_memory_block to modify later.' This clearly distinguishes this tool's role from sibling tools and provides context for when each should be used.

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