zabbix_host_status

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds genuinely useful non-structured context: it is an aggregate over several API calls and deliberately returns a handful of fields rather than thousands of characters of configuration, which tells the agent to expect a compact, possibly lossy response.

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 short sentences, front-loaded with the purpose and scope, then the aggregation behavior, then the routing guidance. Every sentence earns its place with zero filler.

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 single-parameter read tool with no output schema, the description covers what is returned (the four summary areas), how it is produced (aggregated over several calls), and when to choose a sibling instead. Nothing an agent needs in order to call it correctly is missing.

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% and there is only one parameter ('host', documented as name/fragment/identifier). The description reinforces the single-named-host scope but adds no format or syntax detail beyond the schema, so the baseline 3 applies.

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 ('Summarise one host') and enumerates the exact scope of the summary: availability, active problems, data freshness, maintenance. It explicitly distinguishes itself from zabbix_host_investigate and zabbix_hosts, so an agent can pick it without opening sibling schemas.

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 selection condition ('when the user wants a short health check of one named host') and names both alternatives with the condition that selects each: zabbix_host_investigate for the full diagnostic bundle, zabbix_hosts for name-fragment search. No inference required.

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