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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral details ('public', 'countdown is end_time minus now', 'whether it is resolved') but no deeper caveats such as rate limits or freshness guarantees.

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?

One tightly worded sentence states the resource and all key outputs without wasted prose. The most relevant qualifiers ('current', 'read-only, public') are front-loaded.

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 zero-parameter, read-only, public tool with no output schema, the description is sufficient: it tells the agent exactly what fields will be returned and that no input is needed. Nothing essential is missing for correct invocation.

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 and empty schema coverage is trivially 100%, so there is nothing for the description to explain. Baseline for zero-parameter tools is 4, and no additional parameter guidance is needed.

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 clearly identifies the resource ('current Arena epoch') and enumerates the exact data returned: epoch number, start/end time, pool size, and resolved state. This distinguishes it from the numerous get_arena_* siblings such as get_arena_history or get_arena_state.

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 phrase 'current Arena epoch' implies this tool is for fetching the present epoch's summary, but it does not explicitly contrast with alternatives like get_arena_history or get_arena_state. Context is understandable, but no when-not-to-use guidance is provided.

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