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

With no annotations, the description carries the full burden. It transparently discloses the fee rate, remission/exemption conditions, and that it only covers registration fees. It could mention it's a read-only calculation with no side effects, but the provided information is sufficient.

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 a single, well-structured paragraph that front-loads the core purpose and then provides key details. Every sentence is informative and there is no redundancy or wasted words.

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 has 4 boolean/enum parameters and no output schema, the description fully explains the fee logic, conditions, and scope. It provides enough context for an agent to correctly invoke the tool and interpret results.

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?

The description adds significant meaning beyond the schema by explaining how each parameter affects the fee calculation: 'couple doubles document count', 'incomeUnder12k' for 50% remission, 'qualifyingBenefits' for full exemption. Schema coverage is 100% but the description enriches understanding.

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 calculates OPG fees for registering LPAs, with specific fee amounts and conditions. It explicitly differentiates from drafting costs and suitability advice, distinguishing it from siblings like 'calculate_iht' or 'estimate_probate_cost'.

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?

The description sets clear boundaries by specifying 'Registration fees only' and excluding drafting costs and suitability advice. While it doesn't explicitly state when to use this tool over alternatives, the scope is well-defined and implies its use for LPA registration fee calculations.

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