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

Beyond the annotation readOnlyHint=true, the description discloses a critical behavioral trait: the SQL query is date-bounded to prevent lookahead bias. It also specifies the data availability since April 2018 and that percentiles/z-scores are 'leak-free', providing meaningful context for an agent assessing reliability.

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 concise sentences deliver immediate purpose, key technical behavior, and an access-tier tag without any fluff. The front-loaded first sentence clearly states the tool's action, and the remainder earns its place by adding behavior and scope details.

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?

Since there is no output schema, the description covers the essentials: it lists return components, states the time range, and explains the leak-free design. It lacks explicit edge-case handling (e.g., unsupported dates) and authentication nuances, but for a historical read-only dashboard tool it is reasonably complete.

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 the baseline is 3. The description adds extra meaning to the `at` parameter by explaining the supported time range ('since April 2018') and that data used is strictly before the timestamp. It does not add detail for symbol or apiKey, but the enhancement justifies a 4.

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 uses a specific verb 'Replay' and names the resource 'VRP dashboard' with its key components (z-score, percentile, regime, strategy scores). It specifies a clear time scope ('at any minute since April 2018'), effectively distinguishing this historical tool from real-time VRP tools and other historical getters.

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 description strongly implies usage for historical backtesting by emphasizing 'Replay' and 'leak-free' behavior, explaining that the tool only sees data before the `at` timestamp. However, it does not explicitly name alternative tools (e.g., get_vrp) or state when not to use it, so it falls 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.