Related articles or titles

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

Annotations already declare read-only, idempotent, open-world and non-destructive, so safety is covered. The description adds meaningful behavior beyond that: the articles mode returns records with id, title, date and counts, and points to gf_article for full reads, while the similar mode returns full profile objects shaped like gf_games output. That return-shape disclosure matters because there is no output schema. Pagination/limits are unmentioned.

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?

Front-loaded with the core purpose in the first clause, then usage and return shape. Two short paragraphs, no filler. The second paragraph is dense but every clause carries routing or return-format information.

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 3-parameter read tool with no output schema, the description covers purpose, both mode semantics, the slug prerequisite, and an outline of returned fields. Remaining gaps are minor: no statement of result limits, ordering, or behavior on an unknown slug.

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 both enums are documented there, so the baseline is 3. The description still adds value by explaining what each 'what' value actually yields (aggregated post records vs. profile objects shaped like gf_games output), which the schema's one-line enum descriptions do not convey.

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 and resource ('list the articles Gamefa links to a game or film profile') and splits the second mode ('the games/films it shows as similar') explicitly, so the two behaviors behind the single tool are unambiguous. The second sentence routes the agent from gf_games/gf_films, which separates it from keyword-search siblings like gf_search_articles.

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?

Gives a concrete trigger for each mode: 'news and reviews about X' after gf_games or gf_films returned a slug, and 'games like X' for the similar mode. The prerequisite (you need a slug, not a query string) is spelled out. It stops short of naming the alternative sibling for free-text lookup (gf_search_articles), so an exclusion is only implied.

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