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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds useful context beyond these by mentioning 'OpenDota keyless data' (no authentication needed) and enumerating the returned profile fields, providing behavioral transparency about data source and output contents.

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 a single, front-loaded sentence that immediately states the purpose and key data fields. Every word earns its place; there is no redundancy or fluff.

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, read-only lookup tool with one parameter and no output schema, the description sufficiently covers what the tool does, what data it returns, and that it requires no API key. The annotations cover safety and side-effect concerns, making the description complete for this context.

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 schema already provides full coverage of the single parameter 'account_id' with a description ('Steam32 account ID'). The description reiterates that the tool works by account ID but adds little semantic value beyond what the schema already states, so the baseline of 3 applies.

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 clearly states the tool returns a Dota 2 player profile by account ID, listing specific fields (name, country, rank tier, leaderboard rank, win/loss totals). This distinguishes it from sibling tools like search_players, which implies searching rather than direct retrieval by ID.

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 implies usage when you have an account ID ('by account ID'), but does not explicitly state when to prefer this over alternatives like search_players or provide any exclusions. It offers clear context for the primary use case but lacks explicit comparative guidance.

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