getRpiOrderbook

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

Beyond the readOnlyHint annotation, the description discloses additional behavioral details: no authentication required, response format is a 3-element array, up to 50 levels per side, and supported product types. This meaningfully helps an agent understand what the tool returns and what it requires before invoking it.

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?

The description is well-organized with bullets and a clear 'Do not use' section, but it repeats the 3-element array format three times: once in the main description, once in Notes, and once in the Agent hint. The Agent hint largely duplicates earlier content, making the definition longer than necessary.

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?

It covers the use case, alternative tool, response structure, supported products, and authentication needs. However, with 0% schema description coverage, the lack of explicit parameter guidance for symbol, limit, and category leaves a meaningful gap for an agent trying to construct a correct request.

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 must compensate. It does not explicitly explain symbol or limit, and the 'Supported Products' line is only an indirect mapping to the category enum. The mention of 'up to 50 levels per side' hints at limit's semantics but does not state it as a parameter explanation.

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 and resource: 'Retrieve orderbook depth data' that shows RPI order sizes alongside non-RPI sizes. It clearly distinguishes itself from getOrderbook by stating that RPI orders are excluded from the standard orderbook and explicitly naming getOrderbook as the alternative.

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 provides explicit when-to-use conditions ('Use this endpoint when you need to...') with concrete use cases. It also gives an explicit exclusion: 'Do not use this endpoint if you only need regular orderbook depth — use getOrderbook instead.' This is strong routing guidance.

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