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

The annotations already disclose destructiveHint=true and idempotentHint=true, so the description does not need to restate those. It adds useful framing with 'previously declared' and real user scenarios, but it does not reveal additional behavioral traits such as what happens when no rest day exists or whether the action is reversible.

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 compact and front-loaded: it states the action first, then gives usage examples, then supplies a clear inference instruction. Every sentence earns its place, and the structured 'INFER — do not ask' line is easy for an agent to parse.

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?

This is a single-optional-parameter tool with an output schema present and annotations covering mutability, destructiveness, and idempotence. The description covers what the tool does, when to use it, and how to handle the parameter, so 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 is 100%, so the schema already documents the date parameter, its format, and default. The description adds meaningful semantic guidance beyond the schema by instructing the agent to infer the date from the user's reference rather than asking, which directly affects invocation behavior.

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 opens with a specific verb and resource: 'Remove a previously declared rest day.' This clearly differentiates the tool from sibling tools like log_rest_day and list_rest_days, since it targets undoing a prior declaration rather than creating or listing one.

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 gives explicit when-to-use guidance: when the user changes their mind or wants to undo a mistaken declaration. It does not explicitly name alternatives or state when not to use it, but the 'previously declared' qualifier and the examples make the intended context clear.

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