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

Adds real behavior beyond the annotations: rate limiting ("a few messages an hour"), no auth or payment required ("no payment, no account"), and human review ("A person reads it"). The annotations already signal this is a non-destructive write, so the remaining gap is what happens on send/failure (confirmation, rejection when throttled), which is not covered.

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?

Four short sentences, front-loaded with the cost/friction answer ("Free.") and then the action. Every clause carries information: purpose, examples, human review, cost, auth, rate limit.

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 one-shot write with annotations and 75% schema coverage and no output schema, the description covers what to send, privacy constraints, cost, auth and throttling. Only the post-send outcome (acknowledgement or throttle error) is unaddressed, which is a minor gap.

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%, so the schema already documents route, contact and message, and both enums are self-describing. The description's "a bug, an idea or a thanks" and "no secrets or private data" loosely mirror the kind enum and message constraint but add no new semantics. Baseline 3 applies.

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 concrete verb (tell the people who run the service) plus the resource (feedback: bug, idea, thanks), so an agent immediately knows this is a channel to the operators. None of the sibling tools (navigate, extract, create_session, etc.) overlap, so no disambiguation is owed.

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?

"what worked, what failed or what you miss" plus the bug/idea/thanks framing gives clear conditions for use, and it notes there is no alternative path needed. It stops short of stating when NOT to use it (e.g. don't use this for reporting tool errors mid-task versus user requests), so it is clear context without explicit exclusions.

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