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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context by disclosing the returned content areas: live price, liquidity magnet levels, next ETF flow day, call kinds, rules, and that grading comes from OwlChart's own candles. It does not discuss freshness guarantees, rate limits, or response shape beyond a content list.

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 front-loaded sentence that enumerates the returned domains without filler. The final short sentence about OwlChart grading adds relevant context rather than repeating the title.

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?

With no parameters and no output schema, the description must explain the return contents, and it lists the main components an agent would need: markets, live prices, liquidity presets, ETF flow day, call kinds, and rules. It is sufficient for invoking a zero-parameter reference tool, though it could state whether this is a static reference endpoint or a live snapshot in more explicit terms.

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?

The tool has zero parameters, so there are no parameter semantics to explain. The baseline for zero-parameter tools is 4, and nothing in the description undermines that.

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 states the resource clearly: the markets an agent can make a call on in the Owl Arena, along with related reference data such as call kinds and rules. It is more specific than the title alone and distinguishes itself from action-oriented siblings like arena_forecast or show_chart, though it never uses an explicit verb like 'list' or 'return'.

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 by phrases such as 'markets an agent can make a call on' and 'presets for a touch call,' which suggest this is reference data to consult before making an arena call. However, the description gives no explicit when-to-use guidance and does not contrast this tool with siblings like arena_forecast or search_markets.

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