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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the safety profile is known. The description adds 'Auth required' and the forfeit alias, which are useful, but for a destructive mutation it never says what actually happens to the match (voided? opponent awarded the win? rating impact?).

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?

Front-loaded trigger and auth note in a single compact block with an example; nothing wasted. The leading 'End match.' merely restates the title, a small redundancy.

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?

An output schema and annotations exist, so return values and safety are covered elsewhere. However, for a destructive match-terminating tool the description leaves the actual consequence of ending a match unstated, which is the one thing an agent most needs before calling it.

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% and all three parameters are documented in-schema, so baseline is 3. The inline example with match_id reinforces usage but adds no meaning beyond the schema's 'Match id from arena_join / arena_list_matches'.

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?

Specific verb + resource ('End match') with scope narrowed to 'your active match' and an explicit equivalence to arena_forfeit, which lets an agent place it among the many arena_* siblings. It does not distinguish itself from near-neighbors like arena_rematch or arena_leave_queue, but the alias note does most of the routing work.

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 'WHEN: end/void your active match' clause gives a concrete trigger condition, and naming arena_forfeit as an alias tells the agent either name works. No explicit when-not guidance (e.g., do not use after the match has ended), so it stops short of full routing clarity.

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