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

Beyond the readOnly and idempotent hints, the description discloses important non-obvious behaviors: coverage is uneven across legal traditions, an empty glossary is a reader artifact rather than a statement about the act, NULL definitions have two distinct causes, and count represents three populations. It also clarifies which output fields require API-key authentication. This is exactly the kind of context an agent needs to avoid misreporting.

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?

Though the description is longer than average, it is front-loaded with purpose and then organized around distinct caveats that each prevent a different type of agent error. Every sentence earns its place, particularly the warnings about empty glossaries, NULL definitions, and count semantics.

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 compensates by detailing the return semantics: verbatim wording, provision references, `provisions`, `count` as three populations, NULL definition causes, and the `adopts` resolution requiring authentication. This is sufficient for an agent to call the tool and interpret its result 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 coverage is 100%, with the single `work` parameter already described as 'ELI or official number of the instrument, e.g. 32011L0083.' The description does not need to restate this. The baseline of 3 applies because the schema carries the parameter documentation burden.

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 concrete definition: 'The act's glossary: every term it defines, alphabetical, with the publisher's own wording verbatim and the provision that defines each one.' This makes the tool's exact resource and scope clear. It also differentiates it from corpus-wide lookup by stressing 'IN THIS ACT rather than in the corpus at large.'

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 explicitly states when to use the tool: to orient in an unfamiliar instrument or to check a term's meaning within this specific act. It also warns against treating it as a corpus-wide definition source. It does not name the sibling alternative directly, but the 'rather than in the corpus at large' exclusion gives the agent clear routing guidance.

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