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

Annotations already declare readOnlyHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavior: the time window is fixed at 7 days via counts.days rather than being a caller-controlled parameter, and limit caps addedGames and updatedGames separately rather than as a combined total. It does not mention a default limit, ordering guarantees beyond 'newest first', or truncation 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 purpose sentence is correctly front-loaded, but the body is a single dense run-on block that enumerates eight change types inline (claim, gene, evidence, counter, award, credit, digest, rumor). That detail earns its place given no output schema exists, yet inline parenthetical glosses make it harder to scan than a structured list would be.

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 must explain the return shape, and it does so field by field: counts, addedGames, updatedGames with per-type changes, and joseki, plus their sort order. The remaining gaps are minor: no default limit and no statement of what happens when results exceed the limit.

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 0%, so the description carries the burden, and it delivers the key semantic that the raw integer schema omits: limit applies independently to each of the two lists, not to the total. It does not state a default value or note the schema's 1-100 bounds, so compensation is good but not complete.

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 gives a specific verb and resource: it returns what has been added to GameGene in the last `days` days, and it explicitly fixes that window at 7. The closing sentence routes the agent to gamegene_game, gamegene_claims, and gamegene_joseki for details, so the boundary from siblings is partially drawn, though the distinction from gamegene_popular or gamegene_games is not stated.

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: an agent can infer this is a recent-activity feed tool and that the content-reading tools are the follow-up, since both are named. There is no explicit statement of when to prefer it over gamegene_popular, gamegene_games, or gamegene_search, and no prerequisites or exclusions are given.

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