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

Annotations already declare read-only/idempotent/non-destructive, yet the description adds substantial context: listing requires email sign-in and submission checks, some games need review, and nothing is published until the person acts. This is meaningful behavioral disclosure beyond what the structured fields provide.

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?

Content is front-loaded with the primary outcome (returns the listing link) and only then the edge case and prerequisites. Sentences are dense but each carries distinct information; minor verbosity in 'plus what happens next and free ways to get players.'

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 does the work of explaining return content (the link plus next-step guidance, or the existing page). Combined with the sign-in and review caveats, an agent has what it needs; only the exact return shape remains loosely specified.

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 the single param is fully described as a play URL starting with https://. The description restates that it's the game's play link but adds no format or syntax detail beyond the schema, so 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 and resource: returns the foundplay.io listing link for a browser game's play link, prefilled. It also describes the alternate return (existing page) when already listed. It doesn't explicitly reference the siblings check_game or get_boost_options, so differentiation is implied rather than 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 context is clear: the input is a browser game's play link, and the tool handles the 'already listed' case differently from the 'new listing' case. It doesn't name when to reach for check_game or get_boost_options instead, so the routing is only partially explicit.

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