show_date

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

With no annotations, the description bears full responsibility for behavioral disclosure. It only states an action ('Open') without explaining side effects, permissions needed, error handling for invalid dates, or what the tool returns (despite having an output schema). This is insufficient for safe invocation.

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 extremely concise: one sentence for the action and one line for the parameter. It front-loads the core purpose with no filler. Every word earns its place, making it efficient for agent parsing.

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?

For a simple one-parameter tool, the description is adequate but not fully complete. It fails to describe the output (an output schema exists but is not mentioned) and does not clarify what 'open' entails (e.g., is it a UI focus, a popup?). This leaves minor but notable gaps in understanding.

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 schema has 0% description coverage, so the description must compensate. It specifies the date format as 'YYYY-MM-DD', which adds essential information beyond the schema's plain 'string' type. While it does not provide ranges or validation rules, the format hint is valuable and meets most of the need for a single parameter.

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 'Open' and the resource 'Fantastical's mini calendar' with a specific scope: 'to a specific date'. This is distinct from sibling tools which are primarily data retrieval or event creation, making its purpose unambiguous.

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 provided on when to use this tool versus alternatives like get_today or search_events. There is no mention of prerequisites, context, or scenarios where show_date is preferred, leaving the agent without comparative information.

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