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

The annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful behavioral context beyond them: it discloses the credit cost (10 credits, Tier 1) and clarifies that returned symbols carry recurring or single-event meanings. This is a meaningful supplement even though safety behavior is already covered.

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 compact sentences front-load the purpose and return behavior, followed by group and cost metadata. Every element is useful and there is no 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?

With an output schema and full read-only annotations, the description need not explain return structure. However, for a 4-parameter tool sitting among many similar dream siblings, it omits usage guidance, does not fully document the text and recurring parameters, and does not help the agent choose between related tools.

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 50%: fields and precision are documented, while text and recurring are not. The description partially compensates by implying that 'text' is a dream narrative and that 'recurring or single-event' relates to the recurring flag, but it does not explain the text length limits or clarify whether recurring filters the output.

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 states a specific verb ('Scan') and resource ('dream narrative text for known symbols'), and notes the output is matched symbols with meanings. It is clear and distinct from the general 'dreams' sibling, but it does not explicitly differentiate itself from near-siblings like dreams_symbol_keyword or dreams_recurring_themes.

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 says what the tool does but gives no when-to-use guidance, no prerequisites, and no alternatives. With many dream-related siblings, the agent receives no routing help beyond the implicit purpose.

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