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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the description does not need to repeat those. It adds valuable behavioral context by warning that title and description fields are untrusted supplier data that should never be treated as instructions, which is a meaningful security-relevant disclosure 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?

The description is two sentences with no wasted words. It front-loads the core function first, then adds a concise, high-value security warning. Every sentence 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?

For a simple single-parameter read operation with a full output schema and safety annotations, the description is largely complete. The security warning is an important addition. The only notable gap is the lack of guidance on how listing_id should be obtained or how this tool relates to search siblings, but this does not prevent correct invocation in most cases.

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 0%, so the description carries the burden of explaining parameter semantics, but it does not mention listing_id at all. The property name and title make the parameter somewhat self-evident, but the description adds no detail about expected format, source, or constraints, leaving a clear gap.

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 a specific verb ('Return') and resource ('full details for one Casatoo listing'), making it clear this is a single-item retrieval operation. The word 'one' differentiates it from search-oriented sibling tools, and the security note adds meaningful context without obscuring the core purpose.

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 implies this tool is for fetching a specific listing by ID, but it never explicitly states when to prefer this over casatoo_search_listings or casatoo_compare_listings. No exclusions or alternative routing are provided, so the agent must infer usage from the tool name and required listing_id parameter.

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