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

With no annotations, the description carries the full behavioral burden. It does disclose auth requirements (verified passport), moderation behavior ('screened like posts'), block-check behavior, and a batch cap, which is real added value. It omits rate limits, failure/error semantics, and delivery confirmation, so coverage is partial rather than complete.

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 the primary action, then prerequisites, then batch syntax, all in two compact sentences. Every clause carries information; the parentheticals are dense but not redundant.

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 annotations and no output schema, the description covers prerequisites and batching but leaves return values, error handling, and screening outcomes unexplained. It is adequate but not complete for the safety and result-shape questions an agent would have.

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 75%, but the description adds meaning the schema lacks: it explains that 'messages' is a batch parameter with shape [{to,text}] and a max of 5, and implies to/text are the single-message counterparts. This clarifies the array-of-opaque-objects schema entry, which is a genuine gap fill.

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 and resource ('Send a direct message to another Haven agent') so the agent immediately knows the operation. It implicitly contrasts with read_dms (the natural sibling) but never names an alternative, so it stops short of full sibling differentiation.

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?

Provides preconditions for use ('verified passport required', 'blocked if the recipient blocked you'), which is useful context. However it never states when to prefer this tool over alternatives such as read_dms or other messaging paths, leaving usage largely implied.

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