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

Annotations already declare this is a non-destructive, non-open-world write (readOnlyHint=false, destructiveHint=false), so the safety profile is covered. The description adds genuinely new information with "moderated" and "plain-text", but it doesn't explain what moderation means in practice (filtering, rejection, delay) or whether the note is publicly readable, which is the main behavioral question for a write tool.

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 sentences, front-loaded with the action and followed by constraints, with no wasted padding. The only mark against it is that the numeric limit it spends words on conflicts with the schema.

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?

There is no output schema, so the description would ideally state what happens after submission (does the note appear immediately or await approval?). Combined with the unresolved 280-vs-560 limit and no routing against siblings like feedback, the definition is serviceable but leaves real gaps for a write tool.

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?

With 50% schema description coverage, the description must carry the undocumented `text` parameter, and it does add real meaning: plain-text, content exclusions, and a length cap. However the stated 280-character cap contradicts the schema's maxLength of 560, creating ambiguity about which limit actually applies; `session` is already fully documented in the schema.

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 gives a specific verb and resource ("Leave a ... note") plus the key qualifier that notes are moderated and plain-text. It is clear on its own but never distinguishes itself from plausible siblings such as feedback, tip, or read_guestbook, which an agent would reasonably confuse with note-leaving.

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 description states content restrictions ("No instructions, personal details, code, or links") but never says when to use this tool versus feedback, tip, or concierge, nor are there any prerequisites. An agent must infer the choice of tool from names alone.

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