Get a player's achievements

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

Annotations already declare readOnlyHint and openWorldHint, but the description adds key behavioral details: the achievements array caps at 200, unlocked first, and to check returned vs total; returns found:false for private profiles or games with no achievements. These go beyond the annotations and are critical for interpreting results.

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 two dense sentences, packed with valuable information. It is front-loaded with the core purpose, then expands on limitations, alternatives, and prerequisites. While every clause earns its place, the density and multiple parentheticals make it slightly harder to parse quickly.

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 the tool's complexity (capped array, alternative tools, auth requirements, error cases) and the presence of an output schema, the description covers all necessary context. It explains what data is returned, the cap behavior, and when found:false appears, making it sufficiently complete for an agent to use effectively.

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%, so parameters are fully documented. The description adds context by highlighting the role of SteamID64 and appid, noting steamid is optional (falls back to configured STEAM_ID), and language overrides. This extra explanation is valuable but not strictly necessary given the schema.

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 clearly specifies the tool's function: retrieving a player's achievement progress for a single game via SteamID64 and appid. It differentiates from siblings by naming get_game_achievements for the full list and get_global_achievements for rarity without a key.

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 explicitly states when to use the tool (for player-specific progress) and when to use alternatives (get_game_achievements for full game list, get_global_achievements for rarity). It also includes prerequisites (STEAM_API_KEY, public profile visibility) and the found:false outcome, giving clear usage context.

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