UK Property Data

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: it returns specific information (council name, planning system type, URL), explicitly states limitations (no planning application data due to scraping blocks), and provides guidance on next steps (use the direct link for manual browsing). However, it lacks details on error handling, rate limits, or authentication needs, which would be beneficial for a tool interacting with external portals.

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 front-loaded with the core purpose in the first sentence, followed by return details, limitations, and usage guidance—all in four concise sentences with zero wasted words. Each sentence earns its place by adding critical information without redundancy.

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 moderate complexity (single parameter, no output schema, no annotations), the description is largely complete: it covers purpose, returns, limitations, and usage. However, it could improve by mentioning potential errors (e.g., invalid postcodes) or output structure details, as there is no output schema to rely on. The absence of annotations means the description must fully compensate, which it does well but not perfectly.

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 input schema has 100% description coverage, so the baseline is 3. The description adds value by contextualizing the parameter: it specifies 'UK postcode' and implies the tool is tailored for UK planning systems, which enhances understanding beyond the schema's technical definition. However, it does not provide additional syntax or format details beyond what the schema already covers.

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 clearly states the specific action ('Find the planning portal URL') and resource ('for a UK postcode'), distinguishing it from sibling tools like property_search or company_search by focusing on planning portal discovery rather than property data or company information. It explicitly mentions what it returns (council name, planning system type, direct URL) and what it does not (planning application data).

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 explicit guidance on when to use this tool ('Find the planning portal URL for a UK postcode') and when not to use it ('Does NOT return planning application data — scraping is blocked by council portals'), with a clear alternative action ('Use the returned search_urls.direct_search link to browse applications manually'). This directly addresses potential misuse for data scraping.

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