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

Goes well beyond the annotations by disclosing Blind Mode (no applicant personal data), the credit/preview regime, and critically an origin notice that the upstream dataset was emptied and this tool currently returns no records. That last disclosure is exactly the kind of behavior an agent needs and could not learn from structured fields.

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?

Purpose is front-loaded and the dense semicolon-separated clauses are mostly load-bearing. The origin notice partially repeats itself ('Paused since then on every surface' details), which is slightly verbose but justified given its importance.

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?

Covers privacy, cost, rate limits and the paused-dataset reality well, which is strong for a tool with no output schema. However, six of seven parameters remain semantically undocumented, so an agent still cannot construct a meaningful filtered query.

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?

With 0% schema description coverage across 7 parameters, the description must carry the full burden, yet it only explains q (searches all text fields) and the AND-combination rule. authority (a number), reference, decision_date_after/before, page and per_page are left entirely undefined.

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?

States a specific resource ('Planning applications') and its authoritative source ('official planning.data.gov.uk feed, normalized to one schema'), which cleanly distinguishes it from the many sibling query_* tools. An agent can identify exactly what data domain this returns.

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?

Provides useful operational context (filters combine with AND, q searches all text fields, credit cost, preview limit) but never states when to choose this over alternatives or conditions for use. Usage is implied rather than guided.

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