Comparar juegos en común con un amigo

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

The annotations already declare readOnlyHint=true, and the description adds meaningful behavioral detail: it cross-references libraries and returns shared games along with playtime hours per user. It does not mention privacy limitations (e.g., friend's library must be public), but for a simple read-only comparison this is sufficient.

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 a single concise sentence with the action front-loaded ('Cruza') and the purpose immediately stated. Every phrase contributes to understanding the tool's function and output.

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?

This is a simple tool: one parameter, read-only annotations, and a description that explains both the input (comparing with another user) and the output (shared games and hours per user). No output schema exists, but the description adequately summarizes the result for an agent to call it correctly.

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?

The only parameter, friend_steamid, is fully documented in the schema with a description of the SteamID64. With 100% schema description coverage, the tool description adds no further parameter semantics, so the baseline of 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?

The description uses a specific verb ('Cruza') and clearly states the resource (your library with another user's) and the outcome (shared games and hours per user). It is easily distinguishable from sibling tools like get_owned_games, which only return a single user's library.

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 clearly conveys the context: use this tool when you have a friend's SteamID64 and need the intersection of game libraries. It does not explicitly name alternatives or list exclusion criteria, but the use case is clear enough for an agent to select it correctly.

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