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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety bar is low. The description adds genuinely useful context beyond them: cost/auth profile ('Free; no account or subscription required'), the self-attestation nature of the input, and an output caveat that it is not an eligibility determination or full cost figure.

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?

Three tight sentences with the purpose front-loaded, followed by cost/auth details and a scope caveat. Every clause earns its place and nothing is padded.

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 7 required, undocumented parameters and no output schema, the definition leaves significant gaps. It does not explain how the enum inputs (activity, registration_route, approved_person_status) or the boolean flags shape the resulting plan, which is essential for a caller to supply correct inputs.

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% across 7 required parameters; the schema only supplies enum values with no explanations. The description touches the classification concept via 'Self-attest producer classification' but says nothing about is_group, is_marketplace, is_closed_loop, registration_route, or approved_person_status. With the schema silent, the description fails to compensate.

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 verb ('Plan') on a specific resource ('2027 UK packaging EPR large-producer registration'), explicitly sourced from reviewed official guidance. The domain is immediately distinguishable from every sibling tool (NDIS, PFAS reporting, registers, practitioner tools). An agent can tell what this produces without opening the 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?

Usage is implied by the domain ('Plan 2027 UK packaging EPR ... registration') and the clause 'the answer is not an eligibility determination or total EPR cost' sets a partial scope exclusion. However, there is no explicit when-to-use vs. when-not, no named alternative, and no prerequisite guidance.

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