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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds no behavioral context beyond what annotations provide, such as default depth behavior or market scope. It does not contradict annotations, but it also doesn't add value beyond them.

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 a single short sentence with no wasted words. It is front-loaded with the core action and resource. It could arguably be more informative, but for a simple tool it is appropriately concise.

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 simple read-only tool with full schema coverage and safety annotations, the description is mostly complete. However, it doesn't mention the default depth of 10 or clarify what 'market' refers to (e.g., which market type), and there is no output schema to clarify the return format. An agent could call it correctly, but some context is left implicit.

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 (depth and market_id) are already documented in the schema. The description adds no additional meaning beyond the schema. Baseline 3 is appropriate because the schema does the heavy lifting.

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 'Get orderbook for a market' clearly states the verb (get) and resource (orderbook for a market). It is concise and unambiguous. However, it does not explicitly differentiate from the sibling tool get_arena_orderbook, which likely serves a similar purpose in a different context, so it loses a point for lack of sibling differentiation.

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 implies usage: call this when you need the orderbook for a market. It does not state when not to use it or mention alternatives like get_arena_orderbook. The context is clear enough for a simple read operation, but there is no explicit guidance on choosing between this and similar orderbook tools.

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