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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds that each entry includes a story count, which is genuinely useful return-shape context absent from any output schema, but it says nothing about ordering, empty results, or scope limits.

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 short sentences, zero filler, and the primary function is stated first with the downstream use-case second. Every clause earns its place.

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 enumeration tool with no output schema, the description covers both what is listed and what each entry contains (a story count). Adding the nominal follow-up tool name would make it fully self-sufficient, but nothing essential to invoking it correctly is 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 the baseline of 4 applies — there is nothing for the description to disambiguate. The sentence does confirm the listing is unfiltered, which is consistent with the empty schema.

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 gives a specific verb (List) and resource (causes stories are filed under) and even states the return content (story count per cause), so the agent knows exactly what it produces. It doesn't explicitly contrast itself with get_story or search_stories_to_tell, but the resource is distinct enough that confusion is unlikely.

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?

"Use a cause as the filter in a search" tells the agent why the result matters — to obtain a valid filter value for a search — which is useful implied routing. However, it never explicitly names search_stories_to_tell as the follow-up tool or states when this listing should be preferred over other lookups, leaving the agent to infer the workflow.

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