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 'Read-only, public', which is redundant with annotations but reinforces accessibility. It does not disclose return format, pagination, or data freshness, but for a zero-parameter read tool with full annotation coverage, this is acceptable and adds modest value.

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, tight sentence that front-loads the resource, then lists the delivered fields, then states the read-only nature. Every clause carries information; there is zero filler. The field enumeration is the core value and it is delivered immediately.

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 complete enough for an agent to invoke correctly and know what to expect. It names the data elements returned. One could imagine noting freshness or that teams are epoch-scoped, but given the simplicity and annotation coverage, the gap is minor.

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 100% schema coverage (trivially, since there are no properties). The description compensates where needed by explaining exactly what data the tool returns, so there is no ambiguity about invocation. Baseline 4 for zero-parameter tools is appropriate.

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 resource (BLUE and RED arena teams), a specific verb (get/details), and enumerates the exact content (name, NAV, P&L %, epoch wins, portfolio composition). The explicit enumeration of fields plus the read-only qualifier distinguishes it clearly from siblings like get_arena_epoch, get_arena_state, and get_arena_history.

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 provides no explicit when-to-use or when-not-to-use guidance, nor does it name alternatives. However, 'Read-only, public' implies unconditional safe usage, and the readOnlyHint annotation supports that. It is implied that this is the tool to call for team roster/composition details versus siblings like get_arena_state for state, but nothing explicit is stated.

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