Bigquery.Query.Dry Run

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

With no annotations, the description carries the full burden, and it does disclose the two most important behaviors: nothing is billed and the cost rate is $6.25/TiB. It does not state that the query is not actually executed, whether it validates SQL/returns errors, or whether it counts against query quotas—gaps that matter for a dry-run tool with zero annotation coverage.

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?

A single front-loaded sentence with zero waste—verb, outputs, and cost rate all appear immediately.

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?

An output schema exists, so return values need not be explained, and the cost semantics are covered. However, for a tool with no annotations and 0% parameter documentation, the description leaves an agent guessing about SQL dialect, project scoping, and quota side effects.

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 0% for both required parameters, so the description must compensate and does not. It never mentions `sql` (dialect, whether it must be a SELECT, multi-statement support) or `project_id` (which project is billed/queried, default behavior).

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?

States a specific verb (dry-run) and resource (query) plus the exact outputs it returns: scanned bytes and USD cost. The phrase 'billing nothing' strongly implies the contrast with bigquery.query.run, but that sibling is never named, leaving the differentiation implicit rather than explicit.

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?

Usage is only implied: an agent can infer this is the pre-flight cost-estimation step before executing a real query. There is no 'use this instead of bigquery.query.run when...' statement and no stated prerequisites or conditions that would rule it out.

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