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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered; the description's added value is the 'whole form collapses to one call' compaction behaviour and the 'major units' convention. It does not address how the tool resolves the target company when the schema takes no company identifier, nor any return shape beyond the field list.

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 sentences, front-loaded with the output content before the routing rationale and the units caveat. Little waste, though 'Amounts in major units' partially duplicates the schema and the register remark is slightly indirect.

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?

There is no output schema, and the description does enumerate the returned figures, which compensates somewhat. The notable gap is the unstated company-selection mechanism implied by 'the register says when the last accounts were filed dormant' against a schema with no company parameter, leaving an agent unsure how the call is scoped.

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?

With one parameter at 100% schema coverage, the schema already documents shareCapital, its default of 1, and the major-units convention. The description restates 'Amounts in major units' but adds no new meaning, so the baseline 3 is correct.

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 states precisely what the tool produces – the full set of dormant-company figures (share capital, matching cash, zeros elsewhere) – and identifies the trigger condition (companies whose last accounts were filed dormant). However, it never names a verb for the action and does not differentiate itself from close siblings like totals_to_figures, sample_accounts, or get_prior_year_figures, so an agent must infer the distinction from the domain alone.

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?

'For those companies this collapses the whole form to one call' implies the tool is the shortcut when the register shows a dormant filing, which is useful routing information. But no alternative is named and no exclusion is stated for non-dormant companies, so the when-not case is left implicit.

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