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

Annotations cover the mutation/safety profile (readOnly=false, idempotent=true), and the description adds context annotations cannot carry: minimum timer restrictions on billed warehouses, invalidation rules ('A value it cannot use is refused with the reason'), the fact that only open screens re-read rows, and the role requirements for callers.

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?

Dense but front-loaded: the core behavior comes first, followed by alternatives, constraints, and return shape. Every sentence carries information, though the middle section is a long run of constraints that could be broken up for readability.

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 no output schema, the description still documents the return shape ({ triggerId, mode, minutes } or null) and the failure mode (refusal with reason). Combined with parameter and permission notes, an agent has everything it needs to call this correctly.

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; the description still adds meaning beyond the schema by explaining that 0 disables the timer and that 'change' is constrained by the underlying widget's warehouse.

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?

Opens with a specific verb and resource: 'Set how a hosted page refreshes its numbers for everyone who has it open.' It also names the sibling it is not (fastero_set_dashboard_refresh), so the agent can distinguish page refresh from dashboard refresh immediately.

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?

Explicitly routes the agent: dashboards go to fastero_set_dashboard_refresh, pausing goes to fastero_disable_trigger, and this tool is the page-level setting. It also states prerequisites ('change' needs a Postgres/BigQuery widget) and permission requirements, leaving nothing to inference.

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