Update HR zones

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the agent knows it's a non-read-only, non-destructive operation. However, the description adds no behavioral context beyond that—it does not mention what happens to existing zones, whether the update is a full replacement, or any side effects, which is a gap 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 a single sentence, which is extremely brief, but this is under-specification rather than conciseness. It provides no more information than the title and fails to earn its place by adding any useful detail for a tool with five parameters.

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 a mutation with five parameters and no output schema, yet the description gives no information about parameter interactions, what 'updating zones' entails, or return behavior. It is completely inadequate for an agent to select and invoke the tool correctly.

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 only 20% (only 'athlete' is described). The description itself mentions no parameters, leaving max_hr, resting_hr, threshold_hr, and workout_type completely unexplained. Since there is low schema coverage and no parameter information in the description, the agent cannot understand how to use these parameters.

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 identifies the action ('update') and the resource ('heart rate zones'), making it specific enough to know what the tool does. However, it does not distinguish itself from sibling tools like tp_create_zones or tp_update_speed_zones beyond the explicit resource name, so it lacks sibling differentiation.

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. The only contextual clue is the 'athlete' parameter description in the schema, but that is not part of the tool description and does not explain when to use the tool.

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