mem_update

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

No annotations provided, so description carries full burden. It discloses in-place mutation, that id/usage history/read_count are preserved, that parameters replace existing values, and the return format. Lacks error conditions (e.g., what if memory doesn't exist) but sufficient for typical use.

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?

Extremely concise and well-structured: a one-sentence summary, usage guidelines paragraph, parameter list, and return format. Every sentence adds value; no filler.

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 an 8-parameter mutation tool with no output schema and no annotations, the description covers purpose, usage, parameter replacement semantics, and return format. It could briefly note error conditions (e.g., memory not found) but is otherwise 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?

Schema description coverage is 100% (each parameter has a detailed description stating replacement semantics). The description adds a concise summary and groups parameters, but adds limited value beyond what the schema already provides.

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 updates an existing memory in-place, specifying the exact components (body, tags, anchor). It contrasts with sibling mem_save for the topic-upsert pattern, providing clear differentiation.

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?

Explicitly states when to use (memory exists, content outdated/incomplete) and when not to (evolving memories: use mem_save with topic key). Provides clear alternative, which is excellent guidance for an AI agent.

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