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

Annotations already declare readOnlyHint and destructiveHint false, but the description adds valuable behavioral context: the arc is bounded by limit and returned whole rather than paged, instalments are newest first, and English is the fallback for untranslated fields. These are not present in annotations and significantly aid the agent. No contradiction with annotations.

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?

Three sentences that are concise yet informative. The first sentence is somewhat poetic but the second clarifies the concrete behavior, and the third covers prerequisites and language. The description is appropriately sized, with no redundancy.

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?

Given an output schema exists (not shown but indicated) and annotations cover safety, the description covers key aspects: what is returned (all instalments, newest first), ordering, paging behavior (whole rather than paged), language fallback, and required scope. It lacks explicit error handling or rate limits, but these are not critical for a read-only getter. It is sufficiently complete for an agent to invoke 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?

The input schema describes lang and limit in detail, and id is required but undocumented. The description indirectly references limit ('bounded by limit') and language fallback ('English is the fallback'), adding slight meaning beyond the schema. With 67% schema coverage, the description partially compensates but does not explicitly explain the id parameter's role.

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 clearly indicates the tool retrieves a running story's entire arc (a thread) with all its instalments, newest first, and in the same shape as a story on /v1/stories. This differentiates it from siblings like threads_list (which likely lists threads) and stories_get (single story). The verb 'get' is implied by the name and the description makes the resource and scope explicit, though it is slightly poetic.

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?

The description mentions it returns the whole arc rather than paging, implying a distinction from tools that page, and notes it requires the stories API scope. However, it does not explicitly name an alternative tool or state conditions for when to choose this over others. The guidance is implicit rather than explicit.

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