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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description goes beyond them by disclosing the modeling assumptions (equally likely regular styles, replacement by a secret) and explicitly disclaiming that results are 'not official series odds or sealed-case allocation'. This is exactly the kind of context annotations cannot carry.

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?

Front-loaded with the core purpose, then the mode requirements, then the caveat — a sensible ordering. Slightly dense and acronym-heavy ('secretOddsN'), 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?

For a 5-parameter tool with no output schema and no conditional logic in the schema, the description covers the mode/parameter contract and modeling assumptions well. It still leaves the return shape and the meaning of 'boxes' while omitting any distinction from the overlapping sibling tool.

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 0%, so the description carries the burden, and it names three of the five parameters (regularStyles, secretOddsN, probabilityPercent) and explains their conditional dependency on the mode — semantics the flat schema cannot express. It does not explain 'boxes' or the 'target' enum values, leaving a small residual gap.

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+resource ('Calculate independent-box chances') and scopes it to the three target modes (regular style, secret, printed). However, it never distinguishes itself from the very similar sibling secret_pull_probability, leaving the agent to guess which probability tool to call.

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 'Required by mode' sentence gives concrete per-mode parameter requirements, which is useful routing guidance. But there is no explicit when-to-use vs. when-not-to-use and no mention of the sibling secret_pull_probability that appears to overlap; usage is only implied.

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