get_hero_matchups

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

With no annotations provided, the description carries the full disclosure burden. It adds genuinely useful behavioral context by specifying the data source (public matches) and resolving the win_rate ambiguity with 'low win_rate vs a hero means that hero counters this one.' However, it does not disclose response ordering, error behavior, or rate limits, which matters more given zero annotation coverage.

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?

Two sentences with zero waste: the first delivers the purpose and output content, the second adds the interpretive caveat that makes the tool safely usable. Both sentences earn their place.

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 simple single-lookup tool with fully documented schema parameters, the description names the returned fields (games played, win rate), the data source, and how to interpret the key value. The main gap is that with no output schema, the response structure and ordering (relevant to the limit parameter) are left unspecified, but an agent still has enough to invoke and interpret the result.

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 baseline of 3 applies. The schema already documents hero_id resolution via search_dota_entities, limit range and default, and language codes with defaults, so the tool description need not duplicate this. The description adds no parameter detail beyond the schema, which is acceptable at full coverage.

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 (hero performance against every other hero) and the content returned (games played and win rate from public matches). The 'counters lookup' framing and interpretation of low win_rate clearly distinguish this from sibling hero endpoints like get_hero_stats, get_hero_benchmarks, or get_hero_item_popularity.

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 frames the tool as 'the classic counters lookup,' giving an agent a clear condition for when to select it among the many hero-related siblings. It does not explicitly name alternatives or state when not to use it, but the use-case framing is strong enough to guide correct routing.

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