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

With no annotations, the description carries the full burden and does well: it discloses the hash-chain invariant, the seq/prev linkage, and that the return is a partially-signed transaction requiring external signing. It omits failure modes (e.g., prev mismatch), api_key handling, and idempotency behavior, so not a 5.

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?

Four dense sentences, front-loaded with the core action and the chaining constraint. The parenthetical doc pointer is compact and earns its place; no padding.

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 7-param mutation tool with no annotations, no output schema, and 0% schema descriptions, the description covers the novel chaining semantics but leaves the remaining parameters unexplained. Adequate but clearly incomplete.

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%, so the description must compensate; it explains content_hash, seq, and prev semantics well. But from_address, api_key, algorithm, and idempotency_key (4 of 7 params) are untouched, leaving significant gaps for a low-coverage schema.

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 and resource ('Appends one entry to your hash-chained decision log') and implicitly differentiates from siblings like prepare_anchor and verify_decision_chain. An agent can tell what this does without opening the schema.

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?

Gives the key operational rules: 'never send the record itself', 'omit prev only for seq=0', and 'sign and submit yourself'. It doesn't explicitly route to sibling tools (e.g., when to use verify_decision_chain or prepare_anchor instead), which keeps it below a 5.

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