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

Annotations already cover the read-only, non-destructive, closed-world profile, and the description adds real behavioral context beyond that: hard sessions are redacted to just "hard", per-member data is only as fresh as their last plan view ('updated_on'), and the response carries group_message and a conditional page_url. It also discloses the not-in-a-crew behavior.

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 output structure is front-loaded and the args block is separated cleanly at the end. It is denser than strictly necessary (the 'card' framing and group-chat sentence could be trimmed), but no sentence is 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?

Given an output schema exists, the description needn't enumerate return fields, yet it still covers the notable ones (group_message, page_url) and edge cases (no crew, hard-session redaction, stale per-member data). Only the absence of sibling routing keeps it short of complete.

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?

With 0% schema description coverage, the description must carry the lone parameter, and it does: week_of accepts any date in the week and defaults to this week, or on a Sunday to the week ahead. The null-vs-string shape is explained sufficiently for correct invocation.

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 concretely states the resource and scope: the user's crew week drawn as a card, with friends' runs, the club run, matching run days, and the group_message/page_url payload. It is clearly distinct in content from siblings like get_plan or get_daily_summary, though it never names those siblings to route the agent explicitly.

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?

Usage is only implied — the agent can infer this is the tool for 'what is my crew doing this week,' and there are hints about the non-crew case ('Says so when the user isn't in a crew'). But there is no explicit when-to-use/when-not or reference to alternatives such as get_plan for the user's own schedule.

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