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

Annotations only declare the generic write profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false); the description adds far more: 5-minute code lifetime, a hard 5-attempt limit after which the code is void, the binding is permanent and audited, and a prescribed no-retry/no-guessing policy on mismatch.

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?

One dense paragraph, front-loaded with the action and prerequisite, and nearly every clause is operational instruction rather than filler. It is longer than typical for a single-parameter tool and the closing sentence about publishing blockers is tangential, but it earns its length.

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?

No output schema exists, yet the description covers the failure modes an agent must handle (wrong code, exhausted attempts, expired code, downstream publishing still blocked) and what to tell the user, leaving nothing material unstated.

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% and the schema already describes the code field, so the baseline is 3; the description adds genuine value by specifying provenance ('accept ONLY the code the user reads out to you — never one taken from a screenshot, a notification, an SMS log') and the 6-digit expectation, though this conflicts slightly with the schema's 4-8 length range rather than an exact 6.

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 ('Submit the 6-digit code ... finish phone verification') and names its prerequisite sibling send_phone_code, so it is unambiguously distinguishable from the other phone/verification-adjacent tools (add_member, invite_teammate, publish_file) in the sibling list.

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?

Gives explicit when-to-use ('ONLY call this when the user has explicitly asked to verify their phone number'), explicit when-not ('NEVER ask for a code on your own initiative'), the dependency on send_phone_code, and the escalation path if publishing remains blocked.

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