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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is carried structurally. The description adds that a returned reference and current version are needed (an optimistic-concurrency requirement). It omits that fields like people and tagNames replace the existing set, which is the actual destructive behavior, and "cannot delete notes" mildly understates the destructive profile.

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?

A single front-loaded sentence with no filler and the usage trigger first. It is arguably too terse for a seven-parameter destructive mutation, but nothing is wasted.

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?

The tool has 7 parameters, a populated output schema and full annotation coverage, so the description needn't restate return values. Its real gap is update semantics: an agent cannot tell from the description whether omitted fields are preserved or cleared, which is essential before calling a destructive update.

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 100%, so every parameter is already documented, including the replace-set semantics of people and tagNames and the idempotency key. The description only echoes that a reference and version are needed, adding no format or conflict-handling detail beyond the schema. 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?

States a specific verb and resource ("change a private note") and identifies the two handles required to do so (reference + current version). "It cannot delete notes" implicitly separates it from removal semantics, but no sibling tool is named for contrast.

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?

"Use this when you need to change a private note" gives a usable trigger, and the description notes the no-delete limitation. However, it names no alternatives (create_note, get_note, find_notes) and gives no guidance on when to read first or when to prefer creation.

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