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

Annotations already declare read-only, idempotent, and non-destructive behavior; the description reinforces this and adds that it is not separately rate-limited, which is not in the annotations. It also specifies what the return payload includes. This exceeds the baseline but does not discuss error cases or access-control implications, 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?

Three compact sentences: first states the core operation, second adds safety and rate-limit context, third guides input discovery and return content. Every sentence earns its place; no redundant words or 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 single-parameter fetch tool with rich annotations and no output schema, the description covers what the tool does, how to get the ID, what it returns, and that it is safe. It could mention behavior when the ID does not exist, but that is a minor gap for this simple operation.

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 100% and the sole parameter decision_id is described as 'Decision ID from log_decision or list_decisions.' The description reinforces this by pointing to list_decisions, but adds no new semantic depth beyond the schema. Baseline 3 is appropriate.

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 opens with a specific verb and resource ('Fetch one decision-memory record by id') and clarifies that it returns the full record including context, options, risk fields, and hashes. This clearly distinguishes it from siblings like list_decisions (list), log_decision (create), and delete_decision (delete).

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?

It explicitly names list_decisions as the way to find decision ids, telling the agent how to prepare input. It also notes 'not separately rate-limited,' which gives useful operational context. No alternative is needed for a single-record fetch, and the guidance is direct.

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