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

Goes well beyond the annotations by describing the returned artifact in detail: an all-day event ~30 days before the deal ends, containing the full script, offers to ask for, a confirm-in-writing message, and alerts at 9am the day before and on the day. It also confirms 'Nothing is stored', reinforcing the readOnly/idempotent hints with concrete 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?

Three sentences, front-loaded with the core purpose and output artifact, then the construction detail. The middle sentence is dense but each clause carries information the agent needs; little waste.

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?

With no output schema, the description correctly describes the return value (.ics contents and alert timing) and states no persistence. The one gap is that it never clarifies its relationship to get_bill_script/get_bill_help beyond a passing reference, but overall it is complete enough to invoke 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%, so the schema already documents bill, country, provider, and deal_ends fully, including cross-references to getBillScript. The description adds no parameter-level detail beyond what the schema provides, so the baseline 3 applies.

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 a concrete verb+resource ('Calendar reminder to call before a deal ends') and specifies the output artifact (a .ics calendar file). It references the /v1/script relationship, though it does not directly name get_bill_script as the sibling it complements, so differentiation is implied rather than explicit.

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 line about /v1/script emitting this link as add_to_calendar when deal_ends is given implies when the tool is relevant, but there is no explicit when-to-use vs when-not guidance or named alternative among siblings. Usage is inferable but not spelled out.

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