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

Annotations already mark this as read-only and idempotent, and the description adds beyond that: no tick cost, public spectator-level access, and the nuance that historical capture rows may omit captor_kind. These are useful behavioral details an agent could not infer from the annotations alone.

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 dense and information-rich, packed into a long parenthetical that covers return fields, applicability, capture-row caveats, and tick cost. It is not bloated, but the single-sentence structure with multiple embedded clauses makes it slightly harder to parse than necessary.

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 output schema, the description compensates well by enumerating the returned fields and even explaining the captor_kind edge case. It lacks a precise response format, but for this tool the field list and spectator-summary framing give an agent enough to understand what it will get back.

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 the schema already documents both battle_id and session_id. The description reiterates that battle_id can be any active or completed battle but does not add new syntax, format, or parameter-specific guidance beyond the schema.

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 starts with a clear verb-resource pair: 'View the aggregate result of a battle by ID.' It lists the specific return fields and states that it works for any battle, yours or not, which clearly distinguishes it from related tools like get_battle_log or get_battle_status.

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 clear context: it works for active or completed battles, yours or someone else's, and is a query with no tick cost. It does not explicitly name alternative tools or state when not to use it, but the scope is precise enough for an agent to select it appropriately.

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