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

The description explicitly states 'Writes nothing', but the annotation declares readOnlyHint: false, meaning the tool is not read-only. This is a direct contradiction. The description also fails to disclose any other behavioral traits such as idempotency or side effects, though the annotation contradiction is the primary failure.

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-loading the core purpose and adding the key behavioral note about writing nothing. It is efficient and structured without unnecessary verbosity, though it could be slightly more compact.

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 lacks an output schema but indicates the output is 'the exact arguments for entry_add' and instructs to 'pass the JSON straight to entry_add', giving the agent a clear idea of the return format. However, it does not specify error handling, edge cases, or any constraints on event_id/project beyond the schema. The contradiction with annotations further reduces completeness.

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 provides full descriptions for all four parameters (100% coverage). The description does not add additional semantic detail beyond what the schema already specifies, such as formats or examples. The baseline of 3 applies because the schema carries the burden of documentation.

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 action ('Take one event and return the exact arguments'), the resource (an event), and the purpose (converting a meeting to a billable time entry). It distinguishes itself from the sibling listing/search tools by focusing on transformation rather than retrieval.

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 a clear use case: 'so a meeting that already happened becomes billable time without retyping it.' It implies when to use (when you have an event to bill) but does not explicitly exclude alternatives or state when not to use it. The context is sufficient for an agent to infer appropriate usage.

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