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

No annotations are provided, so the description carries the full behavioral burden. 'Check whether' implies a read-only query without side effects, but the description never states that, nor does it describe what happens for unknown/unlisted symbols, auth requirements, or error behavior.

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?

A single front-loaded sentence with zero padding. It is efficient, though its brevity contributes to the gaps in usage and behavioral detail noted elsewhere.

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, so the description should explain what a 'check' returns (boolean, reason string, error for unknown symbol) — it does not. Combined with no annotations and an undocumented symbol parameter, the definition is thin for even a simple validation tool.

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 coverage is 50%: the league enum is documented inline, but the symbol parameter has no schema description. The phrase 'listed symbol' adds a small amount of meaning (the symbol must be an exchange-listed instrument), but the description does not clarify case sensitivity, format, or accepted values beyond the schema baseline.

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: 'Check whether a listed symbol is allowed in a league.' An agent knows this is a validation/lookup tool rather than a mutation. It does not reference any sibling or explain how it differs from arena_leagues or arena_info, so it stops short of full 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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as arena_leagues (which likely enumerates leagues) or arena_info. The agent must infer the calling context entirely.

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