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

Annotations already declare readOnly, idempotent, and non-destructive, covering the safety profile. The description adds output breakdown context, but does not disclose deeper behavioral traits like timezone handling, request size limits, or how optional parameters affect results. No contradiction with annotations.

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, well-structured sentence that front-loads the core function and includes essential details (date range, required params, output composition). No wasted words.

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 rich annotations and presumed output schema, the description covers the core purpose and required parameters, but lacks guidance on the many optional parameters and fails to mention alternatives among siblings. Adequate but with clear gaps.

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 compensate for parameter meanings. It only explains start/end format and implies user_id, but completely ignores the other 5 optional parameters (project, timeout, branches, timezone, writes_only). This is inadequate for an 8-parameter tool.

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 'Fetch WakaTime daily coding summaries for a user over a date range', which is a specific verb+resource+scope. It distinguishes from siblings like durations or heartbeats by emphasizing 'daily' and 'per-day breakdowns'.

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 gives clear context on when to use: when daily summaries over a date range are needed, with required start/end parameters and a format hint. It does not explicitly name alternative tools, but the scope is clear enough for selection among siblings.

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