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

Annotations declare a non-destructive, non-open-world write, and the description adds real behavioral context beyond them: failure with conflict on superseded entries, a possible `needs_confirmation` envelope, and the overall importance of evidence for later settlement. It doesn't describe the success return shape, but with an envelope caveat and failure mode disclosed this is stronger than average.

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?

Front-loaded with the core purpose and follows with routing, failure, and id-sourcing facts. Some narrative (the quoted user anecdote, 'cite it in the lesson') is looser than needed, but every sentence carries usable signal.

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 mutation tool with no output schema, it covers routing, prerequisites, duplicate-avoidance, failure modes, and the confirmation envelope, which are the pieces an agent needs. It omits nothing critical, though it could state whether the appended entry becomes immutable.

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 100%, so the schema already documents all seven parameters including the `kind` enum and `workspace` token rules. The description adds usage flavor (evidence kinds, refId for a Caliper run) but no syntax the schema lacks, so baseline 3 is correct.

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 (records/attaches evidence against an open decision) and enumerates concrete kinds of evidence. It explicitly distinguishes itself from the sibling ledger_metrics_record_reading, so an agent can route without opening either 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 clear when-to-use ('attach it as it arrives and cite it in the lesson'), a when-not ('Metric readings attach themselves via ledger_metrics_record_reading — don't duplicate them here'), and prerequisite sourcing ('Ids come from ledger_entries_list'). Alternatives and conditions are named explicitly.

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