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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description adds genuinely non-obvious context: ordering (oldest first), that rows carry a report-card grade only when one exists, and that calls/readings are copied from published boards. The derived-field semantics of 'flips' and 'since' go well beyond the annotations.

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 trigger is correctly front-loaded, but the middle is a run-on enumeration of return fields, and 'Returns those rows.' is pure filler. The multi-sentence explanation of 'since' is dense and hard to parse in a single reading.

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 carries the full burden of explaining the return shape and it does so field by field, including derived fields. Minor gaps remain: no indication of how many snapshots are typical, whether output is bounded, or what happens for a game with no published boards.

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 100% and the gameId schema entry already includes a concrete example ('2026-w04-ne-buf'). The description only says 'Pass gameId', adding no constraint, format, or failure-mode detail beyond the schema, so the baseline 3 applies.

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+resource+scope: 'every published snapshot for one game, oldest first.' An agent can tell this is a per-game history of published calls rather than a week-wide view. It never names a sibling (get_week_board, get_game, get_changes), so differentiation is inferential rather than explicit.

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?

'Use when you need every published snapshot for one game' gives a positive trigger condition, but with seven siblings including get_week_board and get_changes, no exclusion or alternative routing is provided. The agent must guess whether this or get_week_board is the right source for calls.

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