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

Beyond the annotations (idempotentHint, destructiveHint=false, openWorldHint), the description discloses real behavioral traits: the prior content is replaced but a labelled version is persisted, schema warnings are returned without blocking the write, and on a template the edit propagates to every account reading it. It also notes the tool is not advertised to read-only keys, which annotations alone do not express.

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?

Dense but front-loaded: the replacement action and payload constraints come first, followed by provenance, validation behavior, and blast radius. Every sentence carries information, though the length approaches the point where scanning cost rises.

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, the description covers the write behavior, version persistence, non-blocking validation warnings, and template-wide impact, leaving little an agent must infer. The only minor gap is that the model_id requirement for user-scoped keys is left to the schema.

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. The description restates the 'source' enum meanings, the 5,000-char limit, and that 'summary' labels the persisted version — all already documented in the schema, so it adds little beyond what structured fields provide.

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 gives a precise verb and resource ('Replaces the FINANCE.md attached to a model') plus the payload shape (YAML front matter + body, ≤5,000 chars), which is concretely distinguishable from generic siblings like layerz_read. It also clarifies the template-scoped consequence, making the scope clear without opening the 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?

Usage context is implied through the 'source' semantics and the template-propagation note, but there is no explicit when-to-use / when-not-to-use guidance and no routing to alternatives such as the sibling that sets custom instructions. Adequate but with clear gaps in decision guidance.

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