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

Annotations already cover read-only, open-world, non-idempotent and non-destructive hints, so the safety profile is settled. The description adds value beyond them by describing the return format ('one line each') and the specific fields returned, which is the main behavioral unknown for a no-argument listing call. It says nothing about volume, pagination, or what happens when the account has no reports.

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?

The purpose and the returned fields are front-loaded in one sentence, followed by a short imperative on when to call it. The middle clause listing returned fields is dense but every element (report_type, id, label, metrics and formats, filters and defaults) is actionable information for the follow-up run_report call.

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 input parameters and no output schema, the description carries the full burden of explaining return values, and it does so concretely by enumerating each returned field and noting that filters come with defaults. Nothing an agent needs in order to call this and then chain into run_report appears to be missing.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline of 4 applies. The description correctly avoids inventing filter arguments and instead uses the space to describe output fields.

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 ('List the account's live reports') and adds the differentiator 'of every type', which separates it from the many sibling list_player_reports / list_event_reports / list_session_reports tools. The description also spells out exactly what each returned line contains, so an agent knows the shape of the result without opening anything else.

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 recommends sequencing: 'Call this before run_report to pick a report', which is a clear when-to-use rule. It does not mention when the narrower per-type list_*_reports siblings might be preferable, so the alternative routing is only partially covered.

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