get_ipsec_active_peers

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

Annotations already cover safety (readOnlyHint, idempotentHint, openWorldHint=false), and the description adds real behavioral context beyond them: which fields are surfaced (`state`, `uptime`, `last-seen`, byte counters) and the key caveat that an `established` peer may still carry no traffic. That nuance is exactly the kind of thing an agent cannot infer from annotations or schema.

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?

Front-loaded with the core action and scope, then the phase-1 nuance, then the filter note; no filler sentences. The trailing 'Notes:' block is slightly under-formatted for a single short remark, keeping it just below top marks.

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?

An output schema exists, and the description still helpfully names the returned fields, so return-value explanation is more than adequate. The remaining gap is small but real: with three parameters at 0% schema coverage, an agent still lacks guidance on filter values and on `device` scoping.

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 0%, so the description must carry the parameter burden. It contributes one useful fact — both filters are exact matches — but leaves `state_filter`'s accepted values, the address format for `remote_address_filter`, and the `device` parameter entirely undocumented in either place.

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 precise verb+resource+scope: lists IPsec peers that have a live IKE session, returning uptime and counters. It also disambiguates the parent (phase 1) side from child SAs by naming `get_ipsec_installed_sa`, so an agent can distinguish it from `list_ipsec_peers` and `get_ipsec_installed_sa` without opening a schema.

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?

Explicitly routes the agent to `get_ipsec_installed_sa` when a peer is `established` but child SAs are empty, which is a concrete when-to-use-else instruction. It does not explicitly contrast with the sibling `list_ipsec_peers`, so the neighbor list is only partially resolved.

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