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

The description adds behavioral context beyond the annotations: it specifies a fixed result count (5 games), lists the exact fields returned (event name, kickoff date/time, teams, league, venue), and confirms global coverage including lower divisions. The annotations already declare the tool as read-only, idempotent, and non-destructive, so the description complements them well without contradiction.

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 only two sentences long, with no redundant words. The first sentence front-loads the core purpose and output, and the second sentence adds valuable scope information. Every sentence serves a clear function, making it highly efficient.

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?

Given the tool's simplicity (one parameter, no enums, output schema present), the description covers the key aspects: input source, output fields, and global applicability. It does not address error handling or edge cases (e.g., unknown team_id, no upcoming events), but the presence of an output schema likely handles return structure. Overall, it is sufficiently complete for the tool's straightforward use case.

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 has 0% description coverage for the single parameter 'team_id', so the description must compensate. It clarifies that team_id is obtained from the 'search_teams' tool and implies it is a string identifier. While this adds basic semantic context, it does not provide details on format, length, or validation rules, which would be needed for a higher score.

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's purpose: retrieving upcoming fixtures (next 5 games) for a team using a team_id. It specifies the resource (team events), the action (get upcoming fixtures), and the scope (5 scheduled games). The use of 'upcoming' differentiates it from the sibling tool 'team_events_last', which presumably returns past events.

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 implicitly guides usage by specifying that the team_id comes from 'search_teams' and that the tool works for any league worldwide, including lower divisions. It does not explicitly mention when not to use it (e.g., for past events, use 'team_events_last'), but the context strongly implies the appropriate scenario. A more explicit alternative mention would raise the score.

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