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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds genuinely useful context by disclosing the return shape: 'Returns the skill's instructions as markdown', telling the agent this is a documentation-retrieval tool rather than an action executor.

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 scope statement is front-loaded, followed by usage guidance, trigger phrases, and return format — a sensible order. The single long opening sentence packed with source examples is dense but each item earns its place by helping matching against user 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?

With no input schema parameters and no output schema, the description must carry the return-value burden, and it does ('Returns the skill's instructions as markdown'). Combined with the trigger list and the pairing instruction with the `bryntum` skill, an agent has everything needed to decide to call it.

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 tool takes zero parameters, which is the stated baseline of 4. The description correctly implies no input is required beyond the call itself, and nothing in it suggests parameters that do not exist.

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 gives a specific verb and resource — dragging items INTO a Bryntum Scheduler/Scheduler Pro/Gantt from an external source — and enumerates the source types (sidebar, plain divs, AG Grid, Bryntum Grid). This is clearly distinguishable from sibling skills like skill_bryntum_crud or skill_bryntum_react, which cover different problem domains.

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?

It states when to use it ('whenever items are dragged onto the timeline') and explicitly tells the agent to combine it with the `bryntum` skill, plus a rich set of trigger phrases including failure symptoms ('rejected'/'not working'). What's missing is an explicit exclusion — e.g. that internal, within-timeline drag-and-drop is not covered here.

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