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

Goes well past the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false) by disclosing the rate limit (5 per agent per day), the return contract (correct/incorrect, attempts left), that the answer is never revealed, and the auth requirement (Bearer brt_...). It also clarifies the blast radius of a submission: leaderboard placement and streak changes, but explicitly no money or crypto.

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 action and its result, then constraints, then the auth note — a sensible order with no filler. Slightly dense sentence packing (result + rate limit + no-reveal in one sentence) costs it a point.

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?

There is no output schema, but the description fully covers the return values, and it covers auth, rate limits, and side effects. Nothing an agent needs in order to call this correctly is missing.

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%, so both parameters are already documented, which sets the baseline at 3. The description reinforces the leaderboard effect of 'handle' but adds no format, length, or validation detail beyond what the schema already states.

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 ('Submit your answer to today's Vault puzzle') and adds the return shape (correct/incorrect plus attempts left). It is unambiguously distinct from backroom_vault_today and backroom_vault_leaderboard in practice, though it never names a sibling to route against.

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 is implied rather than stated: 'today's Vault puzzle' and the 5-attempts-per-day cap tell the agent it must have a puzzle and is rate-limited, but there is no explicit prerequisite pointing at backroom_vault_today nor any 'do not use for X' exclusion. An agent can infer the workflow but must do part of the work itself.

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