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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description's 'Read-only' is redundant. However, it adds valuable behavioral context: quotes cover a 12-month period, amounts are in euro cents including VAT, and a discount is returned. This goes beyond the annotations.

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?

Three short sentences, each earns its place: safety indicator, output contents, and call timing. No filler or redundant detail beyond the minor 'Read-only' repetition.

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 single-parameter read-only tool with no output schema, the description is complete: it names the required quantity, explains the returned values, specifies currency and VAT, and gives a clear precondition. An agent has everything needed 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 coverage for the only parameter is 100%, with the schema already explaining the 1-100 range and the bulk discount. The description adds no new parameter semantics beyond restating that N trees are involved, so the 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?

States exactly what the tool does: provides a price quote for sponsoring N trees, with unit price, total, and discount. This is clearly distinct from sibling read tools like get_design or get_forest_stats, which cover other aspects of forest sponsorship.

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 instructs the agent to call this tool before telling the user a price, which is strong practical usage guidance. It does not enumerate alternatives or exclusions, but the tool's single-purpose nature makes that less necessary.

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