opendota_hero_stats

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description goes further by explaining the return structure, skill bracket prefixes (1-8), and the win-rate calculation, which are not available in annotations or schema. It also notes 'Auth: none needed.'

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 tightly packed: a one-sentence summary, a structured return format, an example, and an auth note. Every line adds value, and the field explanation is front-loaded. No wasted words.

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 parameters and no output schema, the description carries the full burden of explaining the response. It fully documents the field names, meaning, and calculation, and even provides an example. The tool is simple, and the description covers all necessary aspects.

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?

There are zero parameters, so no parameter explanation is needed. Baseline is 4 per the rubric. The description focuses on the output fields, which is appropriate for a parameterless tool.

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 uses a specific verb+resource: 'Per-hero win and pick counts broken down by skill bracket.' It clearly states what data the tool returns and distinguishes it from sibling tools like opendota_heroes, which likely provide basic hero info, by focusing on meta stats.

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 'the hero meta' implies it is the go-to for hero performance analysis, and the example adds practical context. However, it does not explicitly contrast with alternatives or provide when-not-to-use guidance, so it stops short of a 5.

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