Add memory

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

Adds real behavior beyond the annotations: a contradicting or restating memory replaces the older one, and the older version stays in history. That supersession-and-versioning rule is exactly the kind of non-obvious effect an agent needs. Size limits are also restated, and nothing contradicts the non-destructive hint.

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?

Three sentences, front-loaded with the trigger, then content shape, then supersession semantics. Slight redundancy in restating the ~800-word / Markdown guidance that the content schema already carries.

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 mutation tool with no output schema, the description covers the write's side effects well but omits how to obtain the required brain id (the list_brains sibling) and how to choose kind, category, confidence, or entityType. Those gaps are significant for a 6-parameter create.

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 coverage is only 33% across 6 params. The description covers 'content' (already described in the schema) and says nothing about brain, kind, category, confidence, or entityType — four of which are undocumented in the schema as well. It leaves the agent guessing where the brain id comes from and how to set metadata.

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?

States a specific verb and resource ('Save a new Brain memory') and implicitly distinguishes itself from update_memory and delete_memory by the word 'new'. An agent can tell immediately this is the creation path.

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?

Gives an explicit trigger condition ('when the user explicitly asks to remember, save, or store something') plus a scoping rule (one memory per coherent fact, don't paste a long document). It does not name update_memory or search_brain as alternatives, so the when-not is only implied.

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