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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavior: webhook/Slack/PagerDuty/Pushover addresses are masked in the response, plus the underlying endpoint (GET /contacts). It does not discuss pagination or how large a full list may be.

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?

Three compact sentences with no filler, and the high-value scoping information (what is returned, what is masked, what the ids are for) is front-loaded. The trailing 'GET /contacts.' endpoint hint is terse and earns its place.

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 read-only single-parameter list tool with a fully documented schema and no output schema, the description covers the return shape and the masking caveat an agent needs. The only real gap is the absence of any guidance on result size or pagination behavior.

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?

One optional parameter with 100% schema description coverage, so the schema already explains customer_id and the MSP omit-case. The description adds nothing about the parameter, which is the expected baseline when the schema carries the load.

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 ('All notification contacts') and enumerates the address types returned (email, SMS, webhook, Slack). Scope word 'All' distinguishes it from the singular nodeping_get_contact sibling without needing to name it.

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 explicit when-to-use or when-not-to-use guidance and no alternative tools are named. The line 'Address ids are what contact groups and checks reference' implies the tool's place in the workflow (getting ids before configuring groups/checks), which is implied usage rather than stated routing.

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