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

The description goes beyond the readOnly/idempotent annotations by disclosing the sense-aware ranking behavior, including specific disambiguation examples (MSO) and the rule for conflicting contexts (return both with an interpretation object). This gives the agent important expectations about edge cases.

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 exactly three sentences: core function, use case, and special behavior. Every sentence carries distinct information, with no redundant filler. The front-loaded structure allows quick comprehension.

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?

The description, combined with annotations and output schema, covers the tool's purpose, typical use, return contents, and edge-case behavior. The limit parameter's default is documented in the schema, and the locale enum is self-evident. The sense-aware context closes potential ambiguity 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?

The schema covers query and limit descriptions; the description enriches query semantics through examples of how ambiguous terms (e.g., 'MSO') are disambiguated based on context. Locale remains undocumented, but its enum is self-explanatory. The description's added context justifies a score above baseline 3.

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 clearly states the tool's function: 'Rank published articles for a query and return them with titles and URLs.' This uses a specific verb and resource, and the phrase 'rather than a single answer' distinguishes it from the sibling 'ask' 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 description explicitly says when to use the tool: 'Use when you want sources to read rather than a single answer.' This implies a contrast with a direct-answer tool and names the alternative behavior. No further exclusion is needed because the context clearly differentiates from the sibling.

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