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

With no annotations, the description carries the behavioral burden. It discloses that the action is a persistent write (stored and later returned), which is useful. However, it omits details like returning a confirmation, potential errors, or limits, so it only partially meets the transparency bar.

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 a single, front-loaded sentence that covers the essential action and outcome without filler. It is appropriately concise, though the brevity slightly undercuts completeness for a tool with no annotations.

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 write tool, the description conveys the primary behavior and its effect (data returned to who_else_is_here). Missing are details about call usage (e.g., whether it returns a confirmation) and any constraints, but given the low complexity, it is marginally adequate.

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 0%, so the description must clarify parameters. It maps 'say' to an optional 'line' and indicates 'name' is required, adding meaning beyond the schema's bare field names. However, it doesn't explain the content or format of the line, leaving some ambiguity.

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 states a clear action ('Stores a name and an optional line') and identifies the resource (the guestbook entry) and its purpose (returned to later callers of who_else_is_here). It distinguishes from siblings by naming the specific reader tool, though it doesn't explicitly mention 'guestbook' or 'sign' as an alternative.

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?

No explicit guidance is provided on when to use this tool versus alternatives like guestbook_sign or deaddrop_leave. The description only states the core behavior without offering context on when to select it over other write tools.

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