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

Annotations already declare readOnlyHint and openWorldHint=false, so 'Read-only' is largely redundant but not contradictory. The description earns credit for behavior annotations cannot express: the operation is 'Free' (no quota/cost), it returns 'headlines plus next_since', and the caller is instructed to store the cursor for the next poll — a genuinely useful protocol detail.

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 tight sentences with the purpose, the date format, and the return/cursor contract front-loaded and no filler. The opening 'Free.' fragment is slightly gimmicky but does carry real signal about cost, so it earns its two words.

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 output schema, the description correctly compensates by describing the return shape (headlines plus next_since) and the polling contract. The only real gap is the undocumented `limit` parameter and any note on what happens when nothing has changed since the given date.

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 0%, so the schema carries only types and a 30-char maxLength. The description rescues the required `since` by specifying accepted formats (YYYY-MM-DD or ISO UTC), but says nothing about `limit` (integer, 1-100), leaving one of two parameters undocumented in both places.

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?

It names a specific resource (Agent Field Kit's cyber-defense advisories) and a specific scope (what's new or updated since a date), and the cursor-based 'only fetch changes' framing separates it from bulk siblings like get_cyber_advisories and search_advisories without the caller opening a schema.

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?

It states the usage context clearly ('pass it on your next scheduled poll so you only fetch changes'), which tells the agent this is the incremental-polling tool rather than the full-listing one. It never names an alternative sibling explicitly, so the agent must infer which tool to avoid, but the use case is unambiguous.

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