Estimate a fetch (no call)

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true. Description adds context: 'no HTTP call or LLM call', 'read-only and free', and describes return structure with confidence/source, which goes 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?

Three concise sentences, front-loaded with purpose and output, followed by usage guidance. No redundant information; every sentence adds value.

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 tool's simple pre-flight nature, output schema is referenced, schema covers parameters, annotations cover safety, and description provides complete usage context including prerequisites and alternative 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 coverage is 100% so baseline is 3. Description mentions adapter_id is from liquid_connect and endpoint optional defaults to primary, which reinforces schema but doesn't add new semantic meaning beyond it.

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?

Description explicitly states 'Pre-flight estimate for a fetch' with specific outputs (item count, bytes, tokens, credits, latency) and contrasts with siblings liquid_fetch and liquid_query, making the tool's role unambiguous.

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?

Clearly instructs to check this before a large liquid_fetch and suggests using liquid_query to narrow the pull if needed. Also notes prerequisite of an adapter_id from liquid_connect, providing explicit when-to-use and alternatives.

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