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

With no annotations, the description carries the disclosure burden. It transparently lists the data fields returned and explains the include_images toggle. However, it does not mention error behavior (e.g., invalid ID, missing data), rate limits, or that the operation is read-only, leaving some behavioral uncertainty.

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, opening with a clear purpose statement. The first sentence is a long enumeration of return fields, but it is structured and information-dense; the second sentence concisely handles the optional parameter behavior.

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 and the presence of an output schema, the description covers the essential return fields and optional behaviors. It lacks only minor details like error handling and explicit rate-limit notes, which are less critical for a single-item fetch tool.

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%, with each parameter well-documented. The description adds value by linking include_images to the output field image_urls and reinforcing the default behavior without parameters, providing practical usage context beyond the schema's basic parameter descriptions.

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 the specific verb 'Fetch' with the resource 'Rightmove listing' and identifies the input as ID or URL. It explicitly enumerates the returned fields, distinguishing it from search tools like rightmove_search which find listings rather than fetch details for a known listing.

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 guidance on when to use include_images (True for full details with photos, False for basic details). However, it does not explicitly compare against sibling tools like rightmove_search or property_report, so the agent lacks explicit instruction on selecting this tool over alternatives.

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