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

Annotations already establish the safety profile (not read-only, not destructive, not idempotent), so the description's main added value is the privacy rule 'Never include anything about your user,' which is real behavioral guidance not present in the annotations. It omits where the submitted data goes or who can read it, which matters given that privacy warning.

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?

Two short, front-loaded sentences with no filler, and the privacy prohibition is placed prominently at the end. Slightly penalized because the terse phrasing creates ambiguity between the optionality of the call and the required agent_name parameter.

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 write tool with no output schema and partial annotation coverage, the description leaves key questions unanswered: what the guestbook is, whether entries are publicly visible, and what note and model should contain. The privacy warning hints at exposure without disclosing it, which is an important omission for a data-collecting call.

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 carry all param meaning, but it only loosely covers two of four: 'which agent you are' maps to agent_name and 'how you found this server' maps to how_found, while note and model are never explained. The 'Optional' framing also reads as conflicting with agent_name being the required field.

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 specific action and its content: record which agent you are and how you found the server, plus a privacy constraint. The verb is implicit ('say') and the resource (a guestbook) only appears in the annotation title, but an agent can still tell what the call accomplishes. No sibling differentiation is offered, though get_task and submit_answer are unrelated.

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 leading 'Optional:' signals that calling this tool is discretionary and not required to complete a task, which is genuine usage guidance. However, it never explains the purpose of signing (e.g., visibility to the server operator) or any condition under which an agent should skip it beyond it being voluntary.

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