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

Goes well beyond the annotations: discloses that archiving unpins the entry, that nothing is deleted, the workspace settings permission requirement, the special agency-entry permission path and memory_id null return, the 409 BRAIN_ENTRY_DERIVED failure for derived entries, and idempotency-key reuse on retries. This is unusually rich behavioral context for a mutation tool.

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?

Front-loads the core action and the archived=true/false mapping in the first sentence, then layers prerequisites and error behavior. Dense but every clause carries operational information; 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?

With no output schema, the description still covers return-relevant behavior (memory_id null, 409 code) and permission prerequisites, which is enough for an agent to call it correctly. Minor gap: no mention of what a successful archive returns or whether workspace_id is required for this operation.

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 57%, and the description adds meaning mainly for the id parameter (use entry.id when memory_id is null) and restates archived semantics already in the schema. brand_id, workspace_id, body, and query remain undocumented, so it only partially compensates for the coverage gap.

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 pair (archive/restore) plus the resource (Brain entry) and the exact flag semantics (archived=true/false). It also distinguishes the operation from deletion ('nothing is deleted'), which separates it from the sibling delete_brain_document.

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 frames the intent ('Intended for knowledge the user asked to retire') and clarifies the reversible nature, so an agent knows when this is preferable to deletion. It does not name a sibling alternative (e.g. update_brain_entry) for non-retirement edits, so it falls short of a 5.

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