get_query_results

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds real behavioral context the annotations don't: the polling loop signal (job_complete false → call again), the pagination contract (pass next_page_token unchanged), and type encodings (NUMERIC as decimal strings, bytes as base64).

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 short sentences, front-loaded with the core action, then the polling rule, then the paging/encoding details. No wasted text and each sentence conveys an actionable constraint.

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 structure needn't be explained; the description still usefully notes how NUMERIC/dates/bytes are represented. Combined with polling and pagination guidance this covers most of what a 6-param job tool needs, with only page_size behavior left unexplained.

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%, so the description carries the parameter burden. It explains how account, location, and project_id should be populated (reuse from submission) and that page_token pages forward, but page_size (with its 1–1000 bounds) and job_id are never described, leaving real gaps.

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 pair and resource: 'Poll a query job or read one result page.' This clearly distinguishes the tool from run_query/dry_run_query siblings, which submit rather than poll jobs, and an agent can tell exactly what it does without opening the schema.

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?

Gives concrete operating rules: 'If job_complete is false, call again later' and 'Reuse project_id, location and account from submission.' That tells the agent when and how to re-invoke, though it doesn't explicitly name run_query as the prerequisite step that creates the job.

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