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

Annotations already establish readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioural context beyond that: figures come 'each with its source and date', appeals are limited to the last 12 months, and there is an explicit epistemic caveat that a five-year-supply figure is the council's own claim while appeal decisions can find otherwise. Minor gaps remain — no statement about behaviour when a location is ambiguous or the authority is not found.

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?

Effectively two dense but well-ordered blocks: what the profile contains, then how to address the authority, closing with scope and cost. Every clause carries distinct information — no filler, no restatement of the title — and the caveat about five-year supply is placed where it matters.

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?

With an output schema present, the description need not explain return values, and it doesn't. For a composite profile tool it covers scope, geography, addressing inputs and the key interpretive caveat, which is close to complete; only ambiguity/fallback behaviour for address resolution is unaddressed.

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 must carry the parameter burden, and it does partially: it identifies `lpa_code` as a GSS code and presents `location`/`postcode` as alternative ways to resolve the same authority. What it omits is whether these are mutually exclusive, which takes precedence if several are supplied, and what happens with none supplied (all three are optional).

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 names a specific resource (a planning authority profile) and enumerates its exact contents: local plans with stage/dates/period/housing requirement, the plan timetable, HDT result and consequence, five-year supply, affordable %, CIL, 12 months of PINS appeal outcomes, and held land layers. That is far more specific than the title alone. It stops short of explicitly distinguishing itself from close siblings such as planning_appeals, policy_context or planning_applications, so it is clear but not sibling-differentiating.

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 covers how to call it — pass `lpa_code` (GSS), or a `location`/`postcode` — and states coverage ('England and Wales. Free.'), which gives useful context on eligibility and cost. However it never says when to prefer this tool over planning_appeals, policy_context, planning_check or area_report, so use-case routing is left to inference.

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