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

With no annotations provided, the description carries the full behavioral burden, and it does disclose the payload shape: each market comes with the number of panels online and the rule that assigns a panel to it. It is silent on read-only status (safe to assume from a list operation), on ordering, and on total result size, so disclosure is partial rather than complete.

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?

One front-loaded sentence that leads with the resource and then the return content, with no filler or repetition. The parenthetical market enumeration is long but earns its place as the only place an agent can learn the valid market identifiers.

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 parameters, no annotations, and no output schema, the description is the only source of return-value information, and it does describe what each entry contains (panel count plus routing rule). Missing are ordering, pagination, and error behavior, but for a parameterless enumeration tool the coverage is adequate.

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, which sets the baseline at 4 per the rubric. The enumerated market names in the description are actually output-domain vocabulary rather than inputs, so there is no parameter semantics gap to fill.

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 states a specific resource (country/language markets) and what it returns (panel counts and the routing rule per market), and even enumerates the market values so an agent knows the taxonomy up front. It does not, however, distinguish itself from sibling list tools such as list_guides or list_services, so an agent must infer the distinction from the name alone.

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?

There is no explicit when-to-use guidance, no mention of prerequisites, and no named alternatives among the siblings (catalog_stats, list_services, search_panels). Usage is only implied — an agent would guess this is for discovering valid market identifiers before filtering other calls, but the description never says so.

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