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

With readOnly/idempotent/openWorld already declared, the description still adds substantial context: free, no key, attribution required, ambiguity never guessed, and the crucial warning that sending an appeal to the wrong body wastes the single free independent appeal since neither service forwards. That is genuine behavioral disclosure beyond the annotations.

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 and return contents are front-loaded, and each sentence (routing, deadlines, record, wrong-body warning) carries distinct information. The single dense paragraph is long, but no sentence is filler.

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 no output schema, the description fully enumerates the return payload — deciding body with source, three deadlines, and POPLA statistics (decided, allowed, allowed share, three-year series, uncontested count). An agent knows exactly what to expect.

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 100%, so the baseline is 3, but the description adds dependency semantics: deadlines are only computable when notice_date is present, and rejection_date is what starts the independent-appeal clock. It clarifies how the dates interact rather than merely restating them.

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 first clause states a specific verb and resource ('One call for a UK private parking charge notice') and then enumerates exactly what is returned: appeals body routing, three computed deadlines, and the POPLA operator record. That precision clearly separates it from siblings like popla_outcomes or denial_clock.

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?

It gives concrete usage conditions — use it when routing an appeal, and 'at the second no as well' after operator and POPLA refusal — plus the failure mode that an ambiguous operator name returns candidates. It never names a sibling tool as the alternative to use instead, so it stops short of a 5.

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