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

With no annotations, the description carries the full burden; it discloses the sort order and the read-only nature implied by 'retrieve', plus the data source (saved highlights/notes). It says nothing about permissions, whether lifecycle/archived items are excluded, or what the results contain beyond highlights and notes.

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, no redundancy, and the behavioral fact (newest first) is front-loaded before the usage hint. Every sentence 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-required-param read tool with fully documented schema and no output schema, the description covers what it returns, ordering, and the intended intent. A brief note on how it differs from sibling retrieval tools would close the remaining gap.

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 coverage is 100% – both url and limit are documented with types, ranges and defaults in the schema itself. The description adds no syntax or behavioral detail (e.g., whether url requires exact match) beyond that, so the baseline 3 applies.

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 names a specific verb and resource ('Retrieve ... highlights and notes') and states ordering ('newest first'), which lets an agent predict the output shape. It does not explicitly differentiate itself from siblings like search_research or get_highlights_for_url, leaving that inference to the agent.

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 gives one use case ('summary of what the user has been reading lately'), which implies when to reach for it. But there are no exclusions and no routing guidance versus search_research or get_highlights_for_url, so an agent must guess which tool wins for a filtered or search-style request.

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