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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuine behavioral context beyond them: that status=open entries carry a derived `lapsed` flag and that lapsed entries should be surfaced when the user asks what needs attention — meaningful with no output schema to document it.

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-loads the ledger's purpose before the usage directives, and each clause maps to an actionable filter. The semicolon-heavy second half packs three filter recipes into one dense sentence, which slightly reduces scannability but doesn't waste words.

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, zero-required list tool with annotations covering safety and no output schema, the description supplies the missing behavioral detail (the derived lapsed flag) and the consult-before-acting workflow. Return shape and pagination semantics remain undocumented, which keeps it short of a 5.

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?

With schema coverage at 100%, the baseline is 3, but the description goes further by explaining how filters compose (use compassPageId to find prior attempts and how they settled; status=open means awaiting evidence) rather than restating field descriptions. It clarifies the intent behind combining parameters, which the schema alone does not.

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 identifies the resource (the ledger: decisions, lessons, observations) and the operation by naming it a filtered list, but the listing verb is more implied than stated. It is distinguishable from siblings like ledger_entries_get or ledger_entries_settle through the filtering framing, though it never explicitly contrasts them.

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 explicit when-to-use guidance ('CONSULT BEFORE ACTING — before proposing a flow change, prompt edit, or process decision') and concrete selection recipes for parameters (compassPageId to check prior attempts, status=open for unsettled expectations, kind=lesson for team beliefs). This is a strong routing instruction rather than a vague hint.

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