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

With no annotations, the description carries the full behavioral burden and does well: it discloses that entries are signed and hash-chained, that each call costs 1 unit, and that authentication uses the workspace key via _meta[satledger/api-key]. It stops short of describing failure modes, idempotency, or what the append returns.

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?

The description is front-loaded with the core action, then adds cost and auth in short sentences. 'This is the thing the workspace is for' is more motivational than informational, but overall it is tight and wastes little space.

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 core write tool with no annotations and no output schema, the description covers the essential behavioral facts (append, signing, cost, auth). However, it does not explain what the call returns, how failures are surfaced, or provide guidance on the required agent_id and kind parameters, leaving meaningful gaps.

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 50%, with kind and agent_id undocumented in the schema. The description adds examples for kind ('a tool call, a decision, a message') but says nothing about agent_id format, detail contents, or the fallback api_key argument beyond what the schema already states. It compensates only partially for the coverage gap.

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 a specific verb and resource: 'Append what an agent did ... as a signed, hash-chained entry,' and gives concrete examples (tool call, decision, message). This clearly distinguishes the tool from read-oriented siblings like list_actions, but it never names an alternative or explicitly contrasts itself with record_usage or timestamp_receipt.

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 gives clear implied usage context ('Append what an agent did' plus examples) and mentions a cost and auth requirement, but it provides no guidance on when not to use this tool or which sibling to choose instead. The agent must infer that list_actions is for reading and record_usage for usage metrics.

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