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

Annotations already declare this read-only, idempotent, non-destructive and closed-world, so the safety profile needs no restating. The description adds the one thing annotations can't convey: 'Returns the skill's instructions as markdown', telling the agent the result is prose guidance, not structured data. It doesn't indicate the volume of that markdown or that it is a two-step retrieval, which keeps it from a 5.

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 purpose and the comparison target are front-loaded in the first sentence, and the return format is stated last. The mid-section is a long list of quoted example phrasings; each one functions as a retrieval cue for intent matching, so it earns its place, but the list is dense enough to be trimmed by a few items without loss.

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 zero-parameter skill-fetch tool with no output schema, the description covers what it does, when to reach for it, what it returns, and which sibling to pair it with. The only omission is scale/scope of the returned skill (which Bryntum products it covers, roughly how much content), which would help an agent decide whether one call is enough.

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 is an empty object with 100% coverage, so the baseline for a zero-parameter tool is 4. The description correctly implies no arguments are needed — the 'request' is expressed through the conversation, not parameters — and nothing is left ambiguous.

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?

Opens with a specific verb and resource: 'Find the built-in Bryntum feature for what the user is describing.' It also carves out the negative space (before writing custom renderers/CSS/overlays), which separates it from skill_bryntum_styling and skill_bryntum_theming without requiring schema inspection.

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?

Gives a concrete trigger condition — requests phrased as outcomes rather than APIs — and backs it with a dozen realistic phrasings an agent can pattern-match against. It also positions the tool relative to the `bryntum` sibling ('use alongside'). It stops short of an explicit exclusion rule (e.g., 'do not call if the user already names the feature config'), so it lands at 4 rather than 5.

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