Intervals.icu MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions that parameters can fall back to environment variables, which is useful context. However, it doesn't describe what 'events' are in this context (training sessions, competitions, calendar items?), the response format, pagination behavior, rate limits, authentication requirements beyond the API key parameter, or error handling. For a data retrieval tool with no annotation coverage, this leaves significant gaps.

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 well-structured and appropriately sized. The purpose is stated concisely in the first sentence, followed by a clear parameter documentation section. Each parameter explanation is brief but informative. There's no wasted text, though the structure could be slightly improved by separating the purpose statement more distinctly from the parameter details.

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 that an output schema exists, the description doesn't need to explain return values. However, with no annotations and multiple sibling tools, the description should provide more context about what constitutes 'events' in this system and when to use this versus alternatives. The parameter documentation is good, but the overall context for tool selection and behavioral expectations is incomplete.

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?

With 0% schema description coverage, the description must fully compensate for parameter documentation. It successfully documents all 4 parameters with clear semantics: what each parameter represents, optional status, default values, and format requirements (e.g., 'YYYY-MM-DD'). The description adds substantial value beyond the bare schema, though it doesn't explain relationships between parameters (e.g., what happens if start_date > end_date).

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: 'Get events for an athlete from Intervals.icu'. It specifies the verb ('Get'), resource ('events'), and source ('Intervals.icu'), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'get_event_by_id' or 'get_activities', which would be needed for a perfect score.

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 provides no guidance on when to use this tool versus alternatives. With siblings like 'get_event_by_id' (for single events) and 'get_activities' (for different data types), the agent has no indication of when this batch event retrieval tool is appropriate versus those other options. The parameter documentation doesn't substitute for usage context.

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