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

Annotations only cover readOnlyHint=false, openWorldHint=true, destructiveHint=false. The description goes well beyond them by disclosing the return behavior (sending confirmation, plus a prepared email link when a reply is requested), a concrete rate limit ('3 messages per day'), and content privacy constraints.

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, each doing distinct work: purpose, usage gate, content prohibition, return behavior and rate limit. Front-loaded with the purpose, zero filler.

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 one-parameter mutation with no output schema, the description supplies everything an agent needs: when it may be called, what it returns, and the rate ceiling. Nothing material is left to inference.

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 100% and the single 'message' parameter already documents its 1000-character cap, so the schema carries the load. The description adds only indirect meaning via the 'no personal data, code, or secrets' content rule, not parameter-level detail.

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 ('Sends a user-confirmed feedback message about this icon server to its maintainer'), plus the scope of what is sent. This is unmistakably different from every sibling (find_brand_logo, get_icon, list_collections, search_icons), none of which are feedback tools.

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?

Gives an explicit hard gate: 'Use this only when the user asks to send feedback and confirms the message.' It also states what must not be included (personal data, code, secrets), which is actionable pre-invocation guidance. No sibling could be confused with this tool, so the absence of named alternatives is not a gap.

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