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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered; the description goes further by disclosing granular failure semantics ('a check that could not run says so rather than passing'), the structure of the verdict, and the rate policy (never metered). This is meaningful behavioral context beyond the structured fields, though return shape details remain sparse.

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-loaded with the operation and then the enumerated checks, with no filler sentences. It is dense and slightly long for a single-parameter tool, but each clause (checks performed, verdict naming, failure handling, rate) carries distinct information.

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 usefully characterizes the verdict as naming every check and flagging checks that could not run, which is the return information an agent needs. Combined with the annotation-covered safety profile and full schema coverage, an agent has enough to call and interpret it, though the concrete verdict format is still not fully specified.

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 there is a single required parameter, so the schema already documents the 64-character hex format. The description references 'the row's receipt hash' but adds no syntax, format, or sourcing detail beyond what the schema provides, making the baseline 3 appropriate.

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 ('recompute and check') and resource ('one receipt'), and enumerates exactly what is validated (receipt hash, prior-row link, day root, anchor state), so the agent knows precisely what the tool does. It does not explicitly differentiate itself from siblings like store_audit or record_subject_history, which are plausibly adjacent, so it stops short of a 5.

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 usage is implied — you call it with a receipt hash to validate a receipt — but there is no explicit when-to-use/when-not statement or named alternative among the record/audit siblings. The 'never metered' note is a cost hint rather than routing guidance.

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