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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds useful behavioral details beyond annotations: it lists returned fields, specifies ordering (current members first), notes that account ids are omitted, and documents the 'not found' response for unknown teams.

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 are front-loaded with the core purpose and return details, then followed by a parameter sourcing note and error behavior. Every sentence earns its place with no 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?

For a simple read-only lookup with one parameter and an output schema, the description covers purpose, return fields, ordering, omitted fields, parameter source, and error handling. Nothing an agent needs to call it correctly is missing.

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 coverage is 100% and the single parameter's description already states 'Required positive OpenDota team ID from opendota_teams or a match response.' The description only reinforces the source from opendota_teams, adding no new syntax or format details 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 states a specific verb and resource: 'Returns the players who played for a Dota 2 team', then enumerates the returned fields. This clearly distinguishes it from sibling tools like opendota_team_heroes or opendota_team_matches by virtue of the resource, though it does not explicitly name those siblings.

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?

It provides a usage hint by saying 'Provide team_id from opendota_teams', which helps with parameter sourcing. However, it does not explicitly state when to use this tool versus alternatives, nor does it give exclusions or conditions beyond the implicit purpose.

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