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

Annotations only say readOnlyHint=false, idempotentHint=false, etc., which tell little. The description adds critical behavioral context: the workspace_key is shown exactly once and cannot be re-revealed, the first ledger_track returns the agent_secret, minting is rate-limited per caller IP, and free tier caps at 3 agents. This goes well beyond the annotations.

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 longer than most but every sentence carries essential onboarding information: no credentials, one-time key, first-write secret, rate limits, free tier cap, and paid alternative. It is front-loaded with the core purpose and next steps, though the paid-path paragraph could be trimmed without losing the tool's primary guidance.

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?

Despite having an output schema, the description provides crucial lifecycle context that the schema alone would not convey: the one-time display of workspace_key, how it connects to the first ledger_track call, and the resulting agent_secret. It covers prerequisites, next steps, limits, and alternative billing—comprehensive for a zero-argument setup tool.

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 tool takes zero parameters, so the baseline is 4. The description reinforces this by stating 'Takes NO arguments on purpose' and explains why, which is useful guidance even though there is no schema to clarify.

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: 'Get a FREE AgentLedger workspace with no credential and no arguments.' It clearly distinguishes this tool from siblings by positioning it as the entry point that every other ledger_* tool depends on, since all others require workspace_key or agent_secret.

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?

Explicitly instructs when to use: 'Call this FIRST if you have no credentials yet.' It names the alternatives (ledger_track, ledger_set_budget, ledger_report, ledger_alerts) and explains why they cannot be used without credentials, plus mentions the paid alternative via POST /v1/billing/x402. No ambiguity remains.

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