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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is known. The description adds value by clarifying that notes are appended (additive, non-destructive) and that the target review must originate from create_review; it does not cover editability or persistence limits of a note.

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 compact sentences with no filler; the core action and scope constraint are front-loaded before the usage examples.

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 simple append tool with full schema coverage, no output schema, and safety annotations present, the description supplies enough context to invoke it correctly. Return behavior and whether notes are editable remain unstated, but those are minor for an additive note tool.

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% and the schema documents all three parameters in detail, including the claim_token authorization and the saved-review token alternative. The description adds only the link between 'review' and create_review, 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?

States a specific verb (append) and resource (free-standing text note), and scopes it precisely with 'not tied to a screenshot ... to a review created by create_review'. This distinguishes it cleanly from the add_screenshot sibling.

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?

Explicitly says when to use it ('for context, steps taken, or a summary of findings between screenshots') and the parenthetical 'not tied to a screenshot' implicitly routes the alternative case to add_screenshot. No explicit when-not or named alternative, so it stops short of a 5.

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