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

Although annotations already declare readOnly/idempotent/non-destructive, the description adds substantive behavioral context beyond them: outputs leave sequential_test_required and exception_test_required null, candidates are not flood-screened, register is capped at 100 with no pagination, and completeness/freshness are unverified. These are exactly the caveats an agent needs to avoid over-trusting results.

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 text is dense but front-loaded with labeled sections (Purpose, When to use, Returns, Limitations, Parameter guidance, Chaining), so an agent can scan it quickly. It is on the long side and some limitation wording is compressed, but each section carries distinct information.

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 and annotations covering safety/idempotency, the description supplies what is missing: the null-outcome contract, register/pagination caps, non-screening caveats, and the site_ref chaining rule. Nothing an agent needs to invoke it correctly is absent.

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 coverage is 100%, so the baseline is 3, but the description adds real semantics: resolved England address, search_radius capped by access, and lpa_boundary_only selecting 'publisher-area-query samples rather than an exhaustive authority search'. That goes beyond the schema's restatement, though it does not detail every parameter.

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 opens with a specific verb and resource ('prepare an England sequential-test evidence checklist and bounded candidate-register sample') and immediately bounds scope with a negative clause ('without determining a requirement, exemption or outcome'). This distinguishes it cleanly from siblings like prepare_biodiversity_review or get_flood_risk without opening either schema.

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?

'When to use: for flood sequential/exception questions and authority-review preparation' gives a clear context, and the Limitations section explains when the output is insufficient ('Zone 1 alone cannot clear all-source/local/future flood issues'). It stops short of naming a specific alternative sibling to use instead in those cases, so it is not full when/when-not/alternative coverage.

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