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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally and the description is not required to restate it. The description adds only the meaning of 'system group' and the optional filter, disclosing no extra behavior such as pagination or return shape.

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?

Two short sentences, front-loaded with the resource and its definition, then the single filter option. No filler, no repetition of the title.

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 simple read-only list tool with a fully documented schema and complete annotations, and no output schema to explain, the description covers the essentials. A brief note on that system groups are the top level of the system-class hierarchy would have made selection among the sibling list tools unambiguous.

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% with all four parameters documented in the schema (page, per_page, search, system_class_id), so the schema does the heavy lifting. The description only echoes the system_class_id filter and adds no format or semantics beyond it, which is the correct baseline for full coverage.

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?

Specific verb+resource ('List system groups') plus a clarifying gloss of what a system group is ('categories of systems, e.g. Heating, Cooling'), which is genuinely useful domain context. It does not, however, distinguish itself from close siblings like list_project_system_groups or list_system_classes, which an agent would need to choose between.

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 phrase 'Optionally filter by system class' implies a usage context, but there is no explicit when-to-use guidance, no prerequisites, and no routing to alternatives such as list_project_system_groups. Adequate but leaves selection between near-identical sibling list tools to inference.

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