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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety and idempotency profile is covered. The description adds return-content context (all-time and 30-day story counts, publication-date span), which is genuinely useful since no output schema exists, but it says nothing about ordering, caching, or whether counts are ever stale.

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?

A single dense sentence with the core noun ('sectors stories are placed in') front-loaded and the returned fields enumerated after. No filler, though the sentence fragment style is slightly clipped and the value of each field is left unstated.

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 zero-parameter, read-only enumeration, the description covers what is needed to call it and even summarizes the payload in the absence of an output schema. It omits ordering, stability of the 18 sectors, and how the counts should be interpreted or refreshed.

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 is the baseline-4 case; there is nothing extra for the description to disambiguate. The empty schema is consistent with the description's implication that the sector list is a fixed set of 18.

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 verb+resource: it lists the sectors that stories are placed in, and it enumerates the returned fields (slug, name, coverage, counts, date span). It does not explicitly distinguish itself from the similarly-shaped siblings list_outlets and list_types, but the resource noun 'sectors' is unambiguous.

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 when-to-use guidance, no prerequisites, and no routing to alternatives such as list_types or list_outlets. An agent must infer from the noun alone that this is the canonical lookup for sector filters in search_stories.

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