calculate_marathon_splits

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

The description states the outputs (5K splits, halfway, final pace) but does not disclose how pace is calculated (e.g., constant pace assumption) or any limitations. No annotations are provided, so the description bears the full responsibility, and it falls short.

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 short but front-loaded with key info. However, the misleading mention of an extra parameter wastes space and could have been corrected. It is structured but not perfectly 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 simple parameter set and presence of an output schema, the description should have been complete, but the discrepancy between described and actual inputs creates confusion. It does not fully cover what the tool does given the actual schema.

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?

Although the schema covers 100% of the single parameter, the description introduces an unsupported input ('distance km') not present in the schema, which is misleading. It does not clarify that target_time_minutes is in minutes, though the schema provides that detail.

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 generates split times for races like marathon/half-marathon and specifies usage for race-day pacing. However, the mention of 'distance km' as an input conflicts with the schema, which only has target_time_minutes, reducing clarity.

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 only says 'Use for race-day pacing' but does not specify when not to use it or mention alternative tools like calculate_running_pace for non-race pacing. The reference to list_bundles for related calculators is too generic.

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