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

Annotations already provide readOnlyHint=true, but the description adds 'no side effects' and clarifies the output format is 'structured JSON', which enhances behavioral understanding beyond annotations.

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 three sentences, all essential. It front-loads the purpose, adds behavioral context, and provides usage guidance with zero redundancy.

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 single optional parameter, no output schema, and annotations, the description fully covers purpose, behavior, usage boundaries, and alternatives. No gaps remain.

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 coverage is 100% (only one parameter: raw). The description adds meaning by explaining the effect of raw: 'Write uname-like text without a JSON envelope', which is not in the schema's description field.

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 uses the verb 'Return' with a clear resource 'system identification' and enumerates five fields. It explicitly distinguishes from sibling tools by stating this tool is not for single-field queries, directing the agent to 'arch' or 'hostname' instead.

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 advises using this tool for 'cross-platform system fingerprinting' and explicitly states when not to use it: 'Not for single-field queries'. It names two alternative sibling tools ('arch', 'hostname'), providing clear decision guidance.

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