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

Annotations already cover readOnly/idempotent/non-destructive/no-open-world, so the description is not obligated to restate safety. It still adds real behavioral context beyond the annotations: the times are in New Zealand time, the payload includes delivery failures ('any problem sending it'), and it requires organisation-owner authorization. Pagination/return-shape details are absent, but the field enumeration largely substitutes for a return-value description.

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 sentences, front-loaded with the action and resource, with the permission caveat placed last where it belongs. The colon-separated field list is dense but each item carries information; no filler.

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 carries the return-value burden and does so by enumerating exactly what each scheduled report entry contains, plus the auth prerequisite. The only real gap is pagination/result-set size behavior, which is minor for a list tool scoped to one organisation.

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?

There is a single parameter with 100% schema description coverage, and that schema text already explains the optional-vs-required rule via list_organisations. The description adds nothing about organisation_id, so the baseline of 3 applies when the schema does all the work.

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?

The description opens with a specific verb+resource ('Lists the organisation's scheduled reports') and then enumerates the returned attributes (report, recipients, frequency/timing, last/next send, send problems, enabled state). That field-level detail makes it plainly distinguishable from create_scheduled_report, update_scheduled_report, send_scheduled_report_now, and list_scheduled_report_types.

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 implied by the verb and the ownership constraint ('Only an owner of the organisation can see...'), which usefully signals when the call will succeed. However, no alternatives are named (e.g., pointing to list_scheduled_report_types for report types or create_scheduled_report to add one), so the agent must infer routing from sibling names alone.

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