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

With annotations already declaring readOnly=false, idempotent=false, and destructive=false, the description adds real behavioral context beyond them: the 20/hour per-owner rate cap and the fact that an omitted author yields a stable, server-generated nickname rather than a new identity per message.

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 sentences, front-loaded with the core action and the rate limit, with no wasted phrasing. The second sentence is somewhat redundant with the schema's author description but adds the stability-over-time angle.

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 with full schema coverage, no output schema, and annotations covering the safety profile, this is largely complete: action, rate cap, and identity behavior are all stated. Minor gaps remain around failure behavior and max length (deferred to the list response).

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 100%, so the schema already documents all three parameters, establishing the baseline of 3. The description's note that the author alias stays stable over time adds a slight nuance beyond the schema's "sem ele o servidor gera um estável," but does not materially extend parameter meaning.

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 verb and resource ("Comenta num canal" = comments on a channel), which an agent can distinguish from siblings like list_comments and delete_comment. It is clear but does not explicitly name or contrast against those siblings.

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?

Usage is implied by the action, and the description adds a rate-limit constraint (20/hour per owner) that shapes when the call will succeed. However, it names no alternatives and gives no explicit when-to-use vs when-not guidance relative to siblings.

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