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

The annotations already establish read-only, idempotent, and closed-world behavior. The description adds valuable transparency by guaranteeing the 'canonical revision verbatim' and 'never rewrites facts', assuring the agent of data integrity. It also previews the output structure (evidence clock, generation mode, quality receipt), compensating for the lack of an output 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?

Two sentences, packed with relevant information, no filler. Every phrase contributes to understanding the tool's purpose and behavior.

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 parameter-less tool with no output schema, the description fully covers what the tool does, what it returns, and any behavioral guarantees. It is self-sufficient and leaves no critical gaps.

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?

There are zero parameters, so the schema provides no ambiguity. The baseline for 0 params is 4, and the description appropriately focuses on the output rather than parameters, adding no irrelevant detail.

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 explicitly states it returns the 'exact full-text Undertow editorial published today' with specific components (evidence clock, generation mode, quality receipt). The verb 'returns' is implied, and the resource is clearly defined. It distinguishes itself from sibling tools by being the only article-related tool.

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 context is clear: use this when you need today's Undertow editorial in full. It does not explicitly mention alternatives or exclusions, but the sibling tools are clearly unrelated (financial metrics), so the intended usage is obvious without needing explicit contrast.

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