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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds valuable context beyond that: the tool returns only 'occurredAt + eventType + status transitions' and redacts operator-only fields (actorId, reason, raw value diffs). This clarifies the public nature of the data and the exact response scope.

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, all packed with essential information: what it returns, when to use it, and what is redacted. No fluff or repetition of schema/annotations.

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 fully explains the return structure (occurredAt, eventType, status transitions) and what is excluded (operator-only fields). For a simple single-parameter read tool, this is sufficient to invoke and interpret the result.

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 schema has one parameter (lenderId) with 0% description coverage. The description mentions 'registered lender' but does not explicitly name or describe the lenderId parameter. Since the parameter is simple and inferable from the tool name, the description partially compensates, but it could still add details about the ID format or example values.

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 specific verb and resource: 'Return the public lifecycle timeline... for a registered lender.' It also explains the exact use case (verifying ACTIVE status at attestation time), which clearly distinguishes it from sibling tools like get_methodology_timeline or get_lending_application_status.

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 this tool is used: 'Used by verifiers to determine whether a lender was ACTIVE at the time a Schema B credit-risk attestation was minted.' It gives a clear context without explicitly naming alternative tools, but the particular scenario is well-defined.

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