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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds real value beyond them: sign-in with email is required, the game goes live immediately, and nothing is actually listed until the person publishes. That is genuine side-effect and prerequisite disclosure.

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?

Four sentences, front-loaded with the primary return value, then the conditional branch and prerequisites. Slightly dense and the 'for free, with the form filled in' clause is a bit tangled, but every sentence carries 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?

With no output schema, the description must convey the return shape, and it does loosely ('the link, plus what happens next and free ways to get players'). Combined with the auth prerequisite and the read-only clarification, an agent has enough to invoke 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?

Schema coverage is 100% with a single well-described parameter, so the baseline is 3. The description adds only that the input is a 'browser game's' play link, a marginal clarification over the schema's own 'Where people play the game, starting with https://.'

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: given a browser game's play link, it returns the foundplay.io listing link pre-filled. It also distinguishes the already-listed branch from the new-listing branch, though it never names the sibling tools (check_game, get_boost_options).

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?

It gives implied usage context ('For a browser game's play link') and describes the alternate branch when the game is already listed, but it never states when to prefer this over check_game or get_boost_options. Usage must be inferred from the scenario description.

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