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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing that the statement is *signed* and includes superseded receipts plus the chain tip — non-obvious contents not derivable from annotations — but says nothing about size, latency, or access requirements.

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?

One dense sentence that front-loads the resource and then enumerates contents; no filler. The nested list of contents is slightly comma-heavy but each clause earns its place.

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?

For a one-parameter read tool with full annotations and an output schema, the description covers what the statement contains without duplicating return-value documentation. The only material gap is the meaning of the default/empty month.

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 0% for the single month parameter, so the description must carry meaning: it does specify the YYYY-MM format, which the schema omits. However, it never explains the empty-string default (presumably current month), leaving the most ambiguous case undocumented.

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 names a specific resource (the signed statement for a month) and enumerates its contents — receipts by result, country, key id, superseding receipts, and the chain tip. It is clearly distinct from list_receipts or verify_receipt, though it never explicitly contrasts itself with them.

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?

Usage is only implied: the month parameter signals a periodic reporting query, but there is no statement of when to choose this over list_receipts or verify_receipt, nor any prerequisite or exclusion noted. An agent must infer the selection criteria from sibling names alone.

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