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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds operational details beyond annotations: the default date window, inclusion of property and contact, and the Europe/Bucharest timezone. It does not mention ordering or limit handling, but the safety profile is fully covered.

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?

One sentence, 16 words, front-loads the core purpose, and includes only necessary specifics: the default window, related entities, and timezone. Every word 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?

Given the tool's simplicity (3 optional parameters, no output schema, read-only annotations), the description covers what it returns (viewings with property and contact), the defaults, and timezone. Minor omissions like sort order and pagination behavior are not critical to correct invocation.

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?

The schema documents fromIso and toIso with defaults, and limit has type/min/max. The description adds the combined default window and timezone context, but it does not explain limit or the exact ISO format beyond the schema. With 67% parameter coverage, the description provides some, but not complete, semantic support.

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 states 'Viewings in a date window (default: the next 7 days), with property and contact,' clearly identifying the resource (viewings), the operation (retrieval), and the scope. It is the only tool about viewings among siblings, so there is no ambiguity or confusion with other list_* tools.

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 provides clear context: this tool retrieves viewings within a date window, defaulting to the next 7 days, and specifies the timezone. It does not explicitly mention when-not-to-use or alternatives, but no sibling tool covers viewings, so the context is sufficient for correct selection.

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