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

Annotations already declare the mutation profile (readOnlyHint=false, destructiveHint=true, openWorldHint=true), so the description only needs to add context — and it does: required OAuth scopes and the fact that each run re-executes the saved query's SQL. It does not warn that writing to an existing spreadsheet at startCell/sheetName may overwrite prior output, which is a meaningful gap for a destructive tool.

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 tightly written sentences with no filler. The core action is front-loaded and the constraint and prerequisite follow in a logical order.

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?

For a 12-parameter creation tool with full schema coverage and an output schema, the description supplies the two things structured fields don't: auth scopes and destination exclusivity. Overwrite behavior on existing spreadsheets and whether schedules are editable afterward remain unaddressed but are secondary.

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 the baseline is 3; the description earns an extra point by stating the destination parameters are mutually exclusive (exactly one of Google Sheets or Slack), an exclusivity rule the schema itself does not encode.

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 and resource (schedule a saved query), the trigger mechanism (cron cadence), and the output surfaces (Google Sheets or Slack). This clearly separates it from siblings like list_schedules and run_schedule_now.

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 clear usage context: it requires write and execute scopes and restricts delivery to exactly one destination. It does not explicitly name alternatives such as run_schedule_now for one-off execution, so the when-not guidance is incomplete rather than absent.

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