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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds substantial behavioral context beyond them: grounding constraints ('add no facts, dates or articles of your own'), citation/disclaimer/label preservation, phrasing rules, vendor-neutrality, and the not_covered response path. This is unusually rich disclosure for a read-only tool.

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 purpose and topic scope are front-loaded, and every sentence carries a distinct operational rule. It is nonetheless a dense block of stacked prohibitions; a short grouped sentence on grounding/citation rules would read more cleanly without losing content.

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 earns its keep: it describes the return shape (points each with a source date), the label states ('Planned, not law yet', 'being re-checked'), and the not_covered case. An agent has everything needed to call it and render the answer correctly.

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% and each parameter carries its own description and enum, so the schema already does the heavy lifting. The description's topic list loosely mirrors the topic enum but adds no syntax or format detail beyond it, so baseline 3 applies.

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 and resource ('Explains the EU DPP Registry and the technical side') and enumerates the covered topics (registration, identifiers, QR/data carriers, data formats, standards, where data is kept) that map directly to the topic enum. It also explicitly distinguishes itself from the sibling scope_check.

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?

Gives an explicit routing rule: 'For who owes, keeps or may hand off a passport, use scope_check.' It also prescribes handling of the not_covered outcome, so the agent knows both when to use this tool and what to do with an unhelpful result.

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