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

With no annotations provided, the description carries full burden. It discloses the tool's educational nature, clarifies that taper relief reduces rate not value, and specifies that it only matters when total gifts exceed the nil-rate band. This provides clear behavioral context beyond the input schema.

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?

Description is two sentences with front-loaded purpose. The first sentence states the core action, the second provides essential caveats. No 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?

The description explains what the tool does (maps gifts to taper bands) but does not specify the output format or content. Since there is no output schema, the description could better indicate what the user receives (e.g., timeline, table). Some gaps remain for complete understanding.

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 field (amount and yearsAgo). The description adds no extra semantics for parameters, relying on the schema's self-explanatory names and descriptions. Baseline 3 is appropriate.

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?

Description clearly states the tool maps lifetime gifts onto the 7-year-rule timeline, specifying it identifies taper bands and when gifts exit the estate. It distinguishes itself from siblings like 'calculate_iht' by emphasizing it is educational only, not a personal tax computation.

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?

Description explicitly states it is an educational timeline, not a personal tax computation, and explains the conditions under which taper relief matters (total gifts exceed £325,000 nil-rate band). It implies when to use (for understanding bands) and when not to (for actual tax calculations), but does not explicitly name an alternative sibling for computation.

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