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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds the non-obvious behavioral fact that the call returns markdown instructions rather than data, and that the content complements rather than replaces the core `bryntum` skill.

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?

Purpose comes first, then scope/exclusions, then trigger phrases, then the return format — a clean front-loaded ordering. The trigger-phrase enumeration is long but each phrase earns its place as a routing signal for this skill-selection tool.

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 parameters, no output schema, and annotations covering safety, everything an agent needs to select and invoke this tool is present: what it covers, what it excludes, how it pairs with the sibling skill, and what it returns.

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, so there is nothing for the description to disambiguate; baseline 4 applies. The absence of parameters is consistent with the description framing this as a retrieval of a fixed instruction document.

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?

States a specific verb and resource: 'Customize Bryntum's built-in event/task editor popup', and scopes it with 'all products except Grid'. It is distinguishable from the generic `skill_bryntum` and framework-variant siblings, though overlap with `skill_bryntum_features` (which could plausibly cover eventEdit/taskEdit) is not addressed.

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 concrete trigger phrases ('edit event popup', 'remove the % Complete field', 'eventEdit'/'beforeEventEdit' config) plus an exclusion ('except Grid') and a pairing rule ('Use alongside the `bryntum` skill'). It stops short of naming which sibling to use instead for Grid or non-editor customization cases.

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