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

With annotations already covering read-only and destructive hints, the description adds valuable behavioral context: the exact fee, payment method and address, and the return value (updated attempts_remaining count). It does not mention idempotency or failure modes, but the annotation idempotentHint=false and the description's 'one additional attempt' phrasing cover the key behavior.

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?

Approximately 90 words, well-structured with a clear opening statement, background context, usage trigger, and fee details. Every sentence contributes and the most critical information (purpose and when to use) is front-loaded.

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 paid mutation tool with two well-documented parameters, an existing output schema, and annotations covering safety, the description provides all necessary context: the trigger condition, payment details, and a preview of the return value. No critical information is missing for an agent to invoke it correctly.

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 parameter descriptions already explain the fee hash and escrow_id thoroughly. The description adds no new parameter-level meaning beyond restating the same information in prose, so it meets the baseline of 3 without exceeding it.

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?

The description opens with a specific verb and resource: 'Purchase one additional submission attempt for a vault that has hit its limit.' It clearly distinguishes this tool from siblings like evaluate_escrow_work and create_escrow_vault by naming the exact trigger condition and the complementary workflow.

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 states when to use: 'When evaluate_escrow_work returns error "submission_limit_reached", call this tool...' It also provides context about default attempt limits and the next step (resubmit with evaluate_escrow_work), leaving no ambiguity about the intended flow.

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