codeforces_upcoming_contests

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

Annotations already cover safety (readOnly, idempotent, non-destructive). The description adds behavioral context beyond those annotations by specifying that results are sorted soonest first and include start time and duration. This tells the agent exactly what to expect in the output, which is valuable. No additional behavioral disclosures (e.g., pagination, rate limits) are necessary for such a simple read-only tool.

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?

A single sentence that leads with the essential information ('Contests that have not started yet') and includes ordering and output fields. No fluff, no redundant wording. It is appropriately sized and front-loaded.

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?

The tool is simple with an output schema present, so return values do not need to be described. Annotations cover safety, and the description covers the core behavior. Sibling tools are clearly differentiated. For an agent to invoke this tool correctly, it has all necessary information: what it returns, how it sorts, and the parameter constraints are in the schema. No gaps.

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%: both parameters (limit and response_format) have clear descriptions in the schema. The tool description does not add any extra meaning to the parameters. Since the schema already fully documents them, 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 states a clear verb+resource: it lists contests that haven't started, with a specific ordering (soonest first) and the fields included (start time and duration). This distinguishes it sharply from sibling tools like codeforces_search_problems or codeforces_rating_history, which serve entirely different purposes. There is no ambiguity about what this tool returns.

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: it is for upcoming contests. However, it does not explicitly mention when to use it versus alternatives or any exclusions. Sibling tools are clearly different, so the context is obvious, but there is no explicit routing guidance. This fits the 'implied usage' level.

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