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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered. The description adds valuable behavioral context beyond annotations: the digest is rolling and expandable, open handoffs are kept in a separate block and never displaced, and read_id/receipt act as a cursor over a frozen window during paginated reads. This meaningfully enriches the annotation-only picture.

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 description is longer than average but every sentence carries distinct operational value: the start-of-session instruction, the digest contents, handoff separation, pagination mechanics, and the sibling distinction. It is front-loaded with the most critical call-time instruction, and no sentence is filler. Slightly dense, which prevents a 5.

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 tool with no output schema, the description covers what an agent needs to invoke it correctly: when to call it, what it returns conceptually, how to continue multi-part digest reads with the cursor, and when to delegate to arroway_read. It also accounts for the session-start workflow and the non-displacement of open handoffs, making it complete in context.

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 100%, and the single optional days parameter is already well documented in the schema with default, bounds, and a usage cue ('Ask for more only when you are picking up work after being away'). The description does not need to repeat parameter details, so the baseline of 3 is appropriate.

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 states a specific verb and resource: it opens a rolling, expandable digest of recent activity across every project the person belongs to, plus a roster of projects. It explicitly distinguishes itself from the sibling arroway_read ('this is the where-do-things-stand read; arroway_read is the task-specific one'), so an agent can select it correctly without opening other schemas.

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 gives an explicit usage rule: 'Call this ONCE at the START of a session, before there is a task.' It also names the alternative arroway_read for full-body content and contrasts session-level catch-up with task-specific reading, providing both when-to-use and when-not-to-use guidance.

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