update_memory

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

With no annotations at all, the description carries the full burden and does well: it discloses partial-update semantics, that empty string means 'keep existing' (non-obvious given the schema defaults), and that replaced content is preserved in history retrievable via get_memory_history — which materially softens the destructive risk. It does not state permission requirements or what happens on invalid memory_id, so it is not exhaustive.

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 critical semantics (partial update, history retention, append alternative) are front-loaded in the first two sentences. The Args block is somewhat redundant with the schema property names, but each line adds the 'leave empty to keep existing' rule, so it earns most of its space.

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?

An output schema exists, so return values need no explanation. For an 8-parameter mutation tool with zero annotation coverage, the description supplies the behaviors that matter (partial update, history retention, sibling routing); the remaining gap is value formats for tags/importance/expires_at.

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 0%, so the description must compensate, and it names all 8 parameters with meaningful semantics ('leave empty to keep existing'), which is essential because the schema gives them empty-string defaults but no descriptions. It stops short of format details — tags delimiter, importance scale, expires_at date format — which remain undocumented anywhere.

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 opens with a specific verb+resource ('Update an existing memory') and immediately qualifies it as a partial update ('Only provided fields are updated'), then names the sibling append_memory as the contrasting behavior. An agent can tell update vs append apart without inspecting either schema.

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?

It gives an explicit routing rule: use append_memory to add context without replacing. That is a real when-to-use/alternative statement. It does not cover other adjacent siblings (delete_memory, save_memory) or prerequisites such as whether the memory must already exist, so it falls short of a full 5.

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