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

Annotations already indicate this is a mutating, non-idempotent operation. The description adds meaningful context beyond the annotations: the target is SOUL.MD, the content is the agent's evolving identity/private notes, and there is an operator vs. ai-service call distinction. This gives an agent useful behavioral understanding without contradicting the annotations.

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 description is two sentences and front-loads the main action before adding context. Every sentence earns its place, and the parenthetical explaining SOUL.MD is concise and valuable.

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 simple two-parameter mutation tool with annotations and no output schema, the description covers the core purpose, the resource being modified, and caller context. It does not describe return values, but this is a minor gap for an append operation where the primary behavior is clearly stated.

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. It partially does: 'append a fragment' strongly implies the append parameter, and 'an Agent's' implies agentIdOrAddress refers to the agent being modified. However, there is no explicit parameter-level guidance about identifier formats, content formatting, or constraints beyond what the schema's minLength already provides.

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 clearly identifies a specific action ('Append') and a specific resource (an Agent's SOUL.MD), and further clarifies that SOUL.MD is the agent's evolving identity/private notes. This distinguishes it from the sibling tool ethora-agent-soul-set, which presumably replaces rather than appends.

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 description implies when the tool is appropriate: when you want to append a fragment to an agent's SOUL.MD rather than replace it. It also provides caller context by noting that it is operator-driven and that the agent can self-edit when called by ai-service. However, it does not explicitly name alternatives or state when not to use it.

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