Claude Code Notification Hooks

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behavioral traits: the tool triggers automatically ('AUTOMATICALLY'), includes an auditory component ('error sound'), and is proactive ('Claude must proactively use this'). However, it doesn't mention potential side effects like rate limits, permissions needed, or whether notifications are logged or displayed in a specific interface.

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 appropriately sized and front-loaded, with the core purpose stated first. However, the list of failure scenarios could be slightly more concise, and the final sentence ('Critical for error awareness - always notify on failures.') reiterates rather than adds new information, slightly reducing efficiency.

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?

Given the tool's moderate complexity (2 parameters, no output schema, no annotations), the description is largely complete. It covers purpose, usage guidelines, and behavioral context well. The main gap is the lack of output information (since no output schema exists), but for a notification tool, the description's focus on triggering behavior is sufficient for most agent needs.

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 description coverage is 100%, so the schema already documents both parameters ('error' and 'details') with their types and constraints. The description doesn't add any parameter-specific information beyond what's in the schema, such as formatting examples or semantic nuances. The baseline of 3 is appropriate when the schema does the heavy lifting.

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 tool's purpose: 'AUTOMATICALLY send error notifications with error sound when anything fails.' It specifies the verb ('send'), resource ('error notifications'), and includes the distinctive feature of an 'error sound.' It distinguishes from siblings by focusing specifically on error scenarios rather than task completion or user action notifications.

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?

The description provides explicit, comprehensive guidance on when to use this tool: 'Claude must proactively use this when: compilation fails, tests fail, file operations fail, network requests fail, validation errors occur, bash commands fail.' It includes a clear directive ('always notify on failures') and distinguishes from siblings by specifying error contexts rather than success or user-interaction scenarios.

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