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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false), and the description goes well beyond them: it identifies this as a write that mutates stored reply text without publishing, discloses that it is not metered, and specifies plan and authorization/scope requirements. That is exactly the extra context annotations do not carry.

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?

Three short sentences, front-loaded with the 'WRITE tool' classification and the key distinction from the publish sibling. Every clause carries information; nothing is padding.

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?

Covers operation, non-publishing semantics, routing to the publish sibling, and auth/plan prerequisites, which is sufficient for a 3-parameter write with no output schema. It could say more about replacement semantics (what happens to an existing reply) and the translate_from_english side effect, but the essentials are present.

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 every parameter is documented in the schema, including the important warning that review_id is Sonar's id rather than Apple's. The description adds no parameter-level detail beyond the schema, 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?

Opens with a specific verb and resource ('replace a review's reply text') and immediately distinguishes the operation from the sibling that publishes it. An agent can tell this apart from sonar_post_review_reply and sonar_draft_review_reply without opening a schema.

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 names the alternative ('Use sonar_post_review_reply to publish') and states the condition that separates the two ('not metered, doesn't post'). Prerequisites (Indie plan, authorized account or write-scoped API key) are stated up front so the agent can pre-check before calling.

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