skylight_add_webcal

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

Annotations only declare readOnlyHint=false and destructiveHint=false, so the description must explain side effects. It does not disclose whether this replaces an existing calendar subscription, whether sync happens immediately, or what happens if the URL is invalid. The description adds almost nothing beyond the 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, direct sentence with no filler. It front-loads the action and object, making it immediately scannable and free of redundant phrasing.

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 mutating tool with no output schema and sparse annotations, the description omits critical operational details: whether frameId is needed in multi-frame setups, what counts as a valid URL, and how this relates to sibling calendar tools. An agent would need to infer or experiment to use 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 coverage is only 50%: sync_url has a description but frameId is undocumented. The description adds no parameter detail beyond restating the sync_url purpose, and it says nothing about frameId defaults, URL format requirements, or constraints. This fails to compensate for the schema gap.

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: subscribe the frame to a webcal/ICS calendar URL. It identifies the specific verb, resource, and input type, making it distinguishable from calendar-related siblings like skylight_create_source_calendar or skylight_link_apple_calendar.

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 about when to use this tool versus alternatives. It does not mention prerequisites (e.g., public URL, existing frame) or explain how this differs from creating a source calendar or linking Apple Calendar.

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