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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered structurally. The description adds one non-obvious behavioral fact — that note content carries ^task markers that must survive a round trip — which is useful context beyond annotations, though it says nothing about pagination, date defaults, or return shape.

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 with the read scope front-loaded and no filler. The second sentence, while useful, is about writing back rather than this tool's own behavior, which slightly muddies the 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?

For a single-parameter, no-output-schema read tool the description is nearly adequate, but it omits the date format, the default when `date` is absent, and what 'recent dates' concretely means — gaps an agent would hit on first invocation.

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% for the single `date` parameter, and the description does not compensate: it never states the expected format (maxLength 10 hints at YYYY-MM-DD), whether it is optional-by-default, or what date is assumed when omitted. 'A day's note and recent dates' gestures at scope but leaves the parameter under-specified.

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?

States a clear verb+resource: reading a day's note plus recent dates, which cleanly distinguishes it from the write_notes sibling. It doesn't name write_notes explicitly, but the read/write split is unambiguous from the tool name and description.

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?

The note about preserving ^task markers 'when writing back' implies this tool is used as the read half of a read-modify-write cycle with write_notes, but that workflow is never stated as guidance. There is no explicit when-to-use or when-not-to-use framing.

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