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

Annotations already cover safety (readOnly, non-destructive, closed-world), so the description correctly spends its words elsewhere: it discloses that the depth block separates text vs parsed amendment coverage and that actsClaimingAmendmentsWithoutEvents signals missing records rather than zero amendments. The 'Free' note adds a cost signal. These are genuine interpretation-level behaviors 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?

Front-loads the purpose, then usage, then two sharp caveats, with almost no padding. The trailing isolated 'Free' is a slightly awkward fragment but a useful cost flag, so structure is strong without being perfectly polished.

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?

An output schema exists, so return-structure explanation is not required; the description still covers purpose, usage triggers, and two field-level gotchas, which is adequate for a zero-parameter diagnostic tool. Only one of the output fields is called out by name, so some interpretive detail is left to the schema.

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?

The tool takes zero parameters, so there is no parameter meaning to convey and the baseline of 4 applies. Nothing in the description misrepresents or omits parameter behavior.

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+resource: corpus counts for acts and provisions, with named dimensions (jurisdiction, regulator, status) and coverage depth. This is clearly distinct from the sibling search/list_acts/resolve tools, so an agent can place it without opening a 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?

Explicit when: 'before searching' and 'when interpreting an empty result' — two concrete triggering scenarios. It does not name an alternative tool explicitly (e.g. list_act_filters), so it stops short of the full when/when-not/alternatives bar.

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