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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds a genuine behavioral limit — a hard cap of 50 results and the consequence that it cannot answer counting questions — which is context an agent needs to interpret results correctly. It omits any mention of result ordering semantics beyond 'most recently created' or what happens when the cap truncates.

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 sentences, both earning their place: the first defines scope, the second defines the exclusion. The core capability is front-loaded and there is no redundant framing.

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?

Return values are covered by an existing output schema, safety by annotations, and the sole parameter by a fully-described schema, so the description needn't do more. The only looseness is the slightly ambiguous phrase 'including the ones in a collection', which doesn't state whether that means cross-collection aggregation is automatic or requires a filter the tool doesn't accept.

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?

With a single parameter at 100% schema description coverage (default 10, max 50), the schema already carries the semantics. The description's 'at most 50 notes' restates the schema's max rather than adding new meaning about the limit parameter or its interaction with the collection scope.

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 and resource ('List the user's most recently created notes') plus a scope detail about included collections, which lets an agent distinguish this from the sibling count_* tools. It does not explicitly separate itself from list_recent_drafts or list_recent_literature_notes, relying on the resource name 'notes' to do that work.

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 an explicit when-not condition with reasoning ('Not for counting... it cannot tell how many the user has'), which directly routes the agent away from count_notes. It never names the alternative tool by name, and gives no guidance on when to prefer search_notes over this recent-list tool.

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