brain_session_capture

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

Annotations already cover idempotency and non-destructiveness; the description adds that already-attributed artifacts are left in place and that this is not a compulsory step. It does not disclose return behavior, permissions, or failure modes, so with annotations lowering the bar, this is adequate but not rich.

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?

Purpose and usage are front-loaded in the first paragraphs, but the explanation includes redundant historical context ('No longer a compulsory ritual' followed by the derived-capture explanation) and a final lifecycle sentence that is tangential. It is readable but not every sentence earns its place.

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 side-effecting 3-parameter tool with no output schema and with annotations, the description provides enough usage context to call correctly, including scope and idempotent ownership behavior. It lacks explicit statements about return values or errors and uses jargon like 'derived capture' and 'receipt' without definition, so completeness is only moderate.

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?

The schema describes only expected_client_key; the description adds meaning for knowledge_ids as durable artifacts and specifies their suitability (outside window/connection/project), plus the 'never steals' rule for already-attributed IDs. It does not discuss session_id or expected_client_key beyond schema, so it only partially compensates for the 33% schema description 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 first sentence identifies a specific action ('Attach durable artifacts') and trigger ('from an explicit user command'). Later text narrows the scope to artifacts the derivation could not see, which differentiates it from automatic capture, though it does not name sibling tools.

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 states when to use the tool: for artifacts created outside the session window, on another connection, or in another project. It also says when it is not needed, because derived capture attributes normal session artifacts and `end` no longer requires a receipt. It stops short of naming sibling alternatives, but the when/when-not guidance is strong.

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