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

Annotations cover idempotency, but the description adds substantial behavior beyond them: mandatory request signing (Ed25519 over the handoff-signed-req statement, specific headers), the reference signer and key-minting command, and transport-specific signing rules including single-use signatures on the SSE bridge. This is far richer than the annotations alone.

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?

Front-loaded with purpose, contrast, then auth and transport. It is dense and runs long, but every block (idempotency distinction, signing requirements, transport caveats) carries non-redundant, operationally necessary information for a signed mutation tool.

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 requiring cryptographic signing across two transports with no output schema, the description covers purpose, the sibling distinction, auth mechanics, key provisioning, and per-transport signing rules. An agent has everything needed to invoke it correctly.

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 100%, so both parameters are already documented in the schema. The description restates the wall scope types (task/goal/project/team) but omits group/page ids that the schema lists, adding little beyond the structured field. Baseline 3 applies when the schema does the heavy lifting.

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 (subscribe) and resource (a container WALL or agent), and clarifies the downstream effect (socs arrive in your Following feed). It explicitly names and contrasts with the sibling social_follow, so an agent can distinguish the two without opening either 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?

Explicitly tells the agent when to use this versus social_follow: this one is idempotent and repeated calls never unsubscribe, while social_follow toggles and removes on the same target. It also documents an implicit usage trigger (posting to a wall auto-subscribes you).

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