wakatime_heartbeats

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It discloses that the tool returns processed, summarized data rather than raw JSON, which is a useful behavioral trait. However, it does not mention potential side effects (likely none), error behavior, or specifics about how filters interact with summaries. It is decent but not exhaustive.

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 two sentences, front-loaded with the main action ('Fetch processed heartbeat data for a date'), and every word adds value. There is no waste or redundancy.

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 there is no output schema and no annotations, the description does a reasonable job explaining the return behavior ('summarized counts by project/file') and the data type ('processed', 'never raw heartbeat JSON'). Minor gaps include the exact shape of the summary and whether branch/project filters affect the summary counts, but the tool is simple enough that this is mostly 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?

The input schema has 100% coverage with descriptions for all three parameters, so the description does not need to add parameter details. The description adds context by mentioning 'for a date', which aligns with the 'date' parameter, but it does not elaborate on branch/project filters beyond what the schema already provides. Baseline of 3 is appropriate given high schema coverage.

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 verb 'Fetch' and the resource 'processed heartbeat data for a date', and explicitly distinguishes from raw data by saying 'summarized counts by project/file, never raw heartbeat JSON'. This differentiates it from siblings like wakatime_durations or wakatime_summaries.

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 context ('for a date', 'summarized counts') and says 'never raw heartbeat JSON', which hints at not using for raw data, but it does not explicitly name alternatives or provide when-not-to-use scenarios. This is implied usage rather than explicit guidance.

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