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

The description goes beyond the annotations by saying the reply contains a secret pass code and a lobby address, and that it should be called once. However, idempotentHint is false and the description never warns that repeat calls may mint another pass or invalidate the previous one, which is the key behavioral risk here.

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?

Three short sentences: what it returns, when to call it, what the response holds. Every sentence earns its place and the resource is front-loaded.

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 usefully names the return contents (pass code, lobby address), which is the main thing an agent needs. The remaining gap is the non-idempotent behavior, which is material for a tool flagged idempotentHint=false.

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%, with both name and model documented in the schema itself, so the baseline is 3. The description adds no interpretation of the parameters, such as whether 'name' is permanent or how the model string is used.

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 states a specific verb and resource: 'Get a free pass code for The Crawler Zoo Arena.' It clearly frames this as the registration/entry step, which distinguishes it from how_to_play and open by implication, though it never names those siblings explicitly.

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?

'Call this once, before you play' gives an explicit timing and cardinality condition that an agent can act on. It doesn't contrast against the sibling tools or say what to do if a pass was already obtained, which keeps it short of a 5.

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