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

Annotations already declare read-only/idempotent behavior. The description adds useful context beyond that: it clarifies that results are 'statutory defaults' and that 'the notice is authoritative', which tells the agent when the computed value may be overridden. No contradiction with 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?

Two sentences with no filler: the first front-loads the inputs and enumerates the returned deadlines, the second adds the authoritative caveat. Every clause earns its place.

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 compensates by enumerating the returned deadline values and the conditional tribunal/POPLA/IAS deadline. It leaves the optional event_date and notice_to_owner_date parameters unexplained, but those are not needed for the core call.

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 80%, so the baseline is 3; the description reinforces the role of notice_type, notice_date, and rejection_date but adds no new meaning for event_date or notice_to_owner_date. The enum descriptions in the schema already carry most of the semantic load.

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 uses a specific verb ('returns') and names the resource (deadlines) plus the exact outputs: discount deadline, challenge/representations deadline, escalation start, and tribunal/POPLA/IAS deadline with a rejection date. This distinguishes it clearly from siblings like check_notice or file_appeal, which address different actions.

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?

It explicitly states the input condition ('Given the notice type and the date on the notice') and the optional rejection-date branch, making it clear when to call it. It does not name alternative tools or exclusion cases, so it stops short of a 5.

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