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

Annotations already cover readOnly/idempotent/non-destructive/closed-world, and the description adds substantial behavior beyond them: short-form IDs are resolved to a full UUID first, `rev` is null when never indexed, and passing it back makes a later write FAIL rather than clobber a concurrent edit. It also discloses that built-in Muninn skills come back read-only and are marked `builtIn: true`.

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 core action is front-loaded in the first sentence, and every subsequent sentence carries information. It is dense with em-dash asides and the skill paragraph sits last as a related tangent, so it is slightly longer than it needs to be, but nothing is pure filler.

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 read tool with annotations and no output schema, the description covers return semantics (`rev` and its null case), ID resolution, and the special skill path. It omits error behavior for unknown or ambiguous prefixes, which is the only notable omission.

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% so the baseline is 3, but the description adds semantics the schema does not: prefix IDs are acceptable and are resolved before use, and a full ID sourced from a <muninn_skills> location behaves differently (opens read-only skill instructions). That is real added meaning over the one-line schema doc.

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 (Retrieve) and resource (a single memory) and scopes it by ID, which cleanly separates it from the list/query/search siblings. The short-form ID resolution and the built-in-skill retrieval path are both named explicitly, so an agent knows exactly what this call returns.

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 concrete conditional guidance for the `rev` value: carry it only when you read now and write later, since a read-then-immediately-write needs nothing. It also explains the one non-obvious usage path (reading a built-in skill's instructions via its <muninn_skills> id). It never states when to prefer this over muninn_memory_search/query/artifact_get when you don't already hold an ID, which is the remaining gap.

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