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

Annotations already carry readOnlyHint=true and destructiveHint=false; the description productively reinforces and elaborates with 'Read-shaped tools only (anything that buys, sells or writes refuses)' and the in-memory/no-write framing. It adds multi-tenant context (Rokha's sandbox, 'their data comes back as it is') beyond the annotations. No contradiction with the annotation set.

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 first sentence is tightly front-loaded and earns its place, and the 'Read-shaped tools only' line is informative. But the tail — 'a live seat on The Wall', 'called through their seat', and the registry URL — is largely promotional noise that does not help an agent invoke the tool. Moderate verbosity reduces an otherwise clean opening.

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 validation tool with a single deeply nested manifest and no output schema, the description omits how results are reported (what invalid looks like, whether it returns per-skill findings). The input side is well covered by the schema, but the agent is left guessing at the return contract of a tool whose entire purpose is returning a verdict.

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 0%, so the description must compensate, and it partially does: it maps the manifest's intent (validating the stack's catalog identity and skill IDs). However, it never explains how to construct the manifest input or what the returned validation verdict looks like. The rich schema (patterns, enums, minItems) carries the structural burden, so the description adds only loose semantic framing — a middle score 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 opening clause 'Validate an agent-selected in-memory AAS stack, its pinned catalog identity, and every selected skill ID without writing it' names a specific verb (validate), resource (AAS stack, catalog identity, skill IDs), and a distinguishing trait (no-write). It is clear against the broader sibling set (e.g., compose_stack writes, diff_stack compares), though it never explicitly names a sibling to contrast with.

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?

The 'without writing it' phrasing implies this is the dry-run/checking option versus a composing/writing sibling, but no alternative is named and no when-to-use/when-not-to-use condition is stated. The guidance is implied rather than explicit, leaving the agent to infer the boundary against compose_stack.

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