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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds valuable behavioral context: the payment start rule under 38 CFR 3.31, rate table source difference (published vs reconstructed), the assumption of constant dependent status, and the specific limitation that it handles only increases and refuses pre-1990 effective dates. This goes well beyond what annotations provide, giving the agent a thorough understanding of the tool's 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?

The description is relatively long but densely packed with necessary details. It front-loads the primary use case and then logically organizes assumptions, rate sources, and limitations. Every sentence adds value, though some redundancy exists (e.g., mentioning 'increase only' twice). Overall, it is appropriately structured for the complexity of the tool, without unnecessary fluff.

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?

Given the tool's complexity (7 parameters, no output schema), the description is remarkably complete. It describes the output (per-month breakdown, assumptions, disclaimer), explains the rate table methodology (published vs reconstructed), notes the critical rule about payment start date, and specifies exclusions and limitations. This fully equips an agent to call the tool correctly and interpret results, despite no explicit output schema.

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% with descriptions for each parameter, so the baseline is 3. The description adds meaning beyond schema by clarifying how parameters are used: e.g., effectiveDate determines the period, adjudicationDate (though schema says defaults to today) is explained as defining the end of the period (through month of adjudication). It also explains that isTdiu treats as 100% for monetary calculation, which is not in the schema's description. This extra context elevates the score one point above baseline.

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 clearly states it estimates retroactive back pay given an effective date and rating increase, and explicitly distinguishes from sibling tools like lookup_compensation_rate (which likely retrieves rates) and calculate_combined_rating (which combines ratings). It specifies the output (per-month breakdown, assumptions, disclaimer), making its purpose unambiguous.

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: 'Use this when a veteran gives an effective date and a rating increase and asks what the retroactive amount would be.' It also gives exclusions (does not set effective date, does not report authorized amount) and limitations (increase only, pre-1990 refused). However, it does not mention alternative tools by name, but the context is clear enough for an agent to decide.

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