delete_custom_item

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

With no annotations, the description carries the full burden of behavioral disclosure. It states that the tool deletes a custom item, implying destructive effect, but says nothing about irreversibility, permissions, impact on related data, or error behavior. The .env fallback for athlete_id and api_key is a useful behavioral detail, but the overall transparency is thin for a mutation 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?

The description is compact and front-loaded: one clear purpose sentence followed by a tight Args list. Every sentence earns its place, with no filler or redundant content.

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 description fully covers the parameter semantics and the main operation, and an output schema exists, so return values are not required. However, it lacks usage guidance, a permanence warning, and any clarification of what exactly is deleted or not deleted. Given the zero annotations and destructive nature, a few more sentences would make it complete.

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 description coverage is 0%, so the Args section must compensate. It does so effectively: item_id is described as the custom item ID to delete, while athlete_id and api_key are explained as optional with .env fallback. This adds meaningful context beyond the bare schema, especially the default behavior.

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: 'Delete a custom item for an athlete from Intervals.icu.' This clearly distinguishes it from siblings like delete_event, get_custom_item_by_id, create_custom_item, and update_custom_item. The agent can identify the tool's exact purpose without opening the schema.

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?

No guidance is given on when to use this tool versus alternatives such as delete_event or update_custom_item. There are no prerequisites, no exclusions, and no mention of when deletion is appropriate or not. The description only states what the tool does, not when to select it.

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