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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint=false, destructiveHint=false), so the bar is lower. The description adds genuinely useful domain context: `topic` reflects Moon Catcher Wire's own keyword rules rather than TSP's model, which an agent could not infer from structured fields. It says nothing about result size, ordering, or the `limit` default, so it stops short of rich behavioral disclosure.

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 description is front-loaded with the core purpose and then walks the filters in the same order as the schema, one clause each, with no filler. Every sentence conveys filter semantics.

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 read-only list tool whose annotations already carry the safety profile, the description covers the filters adequately. However, with no output schema it could state what a story record contains or how `limit`/ordering behaves, and that gap keeps it at minimum-viable-plus rather than complete.

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?

Schema description coverage is only 40%, so the description must carry weight, and it does: it explains that `ticker` matches TSP ticker tags, `topic` matches MCW topic rules (with a pointer to mcw-list-topics), `since_hours` bounds by publication time, and `breaking_only` keeps high-impact wires. Only `limit` is left undocumented, which is the reason it is not a 5.

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 clear verb+resource ("Stories with filters") and enumerates the filter dimensions, so an agent knows this returns a filtered story list. It distinguishes its `topic` model from TSP's and points to mcw-list-topics, but it never explicitly separates itself from mcw-search or mcw-get-story, so sibling differentiation is partial.

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 or when-not-to-use guidance, and no comparison against mcw-search or mcw-get-story. The mcw-list-topics reference is a cross-link for discovering topic slugs, not a routing alternative.

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