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

Annotations only state readOnlyHint=false, openWorldHint=false, idempotentHint=false, destructiveHint=false, which are not informative. The description compensates by revealing critical behavioral traits: the post is public under the user's handle and there is no delete, making it irreversible. It also discloses the 409 nudge flow for negative replies and the confirm:true override, plus the requirement to ask before using image_url. This significantly exceeds the structured metadata.

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?

The description is moderately long but densely packed with essential information, front-loading the primary action first. Every sentence contributes (e.g., cap_slug behavior, approval requirement, 409 handling). It is structured logically from main purpose to content guidance to error handling. A slight deduction for length; it could be trimmed slightly, but overall it is efficient.

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?

Given the tool's complexity (7 parameters, no output schema, weak annotations), the description is remarkably complete. It covers what to post, how to reply, how to attach capabilities, code blocks, and images, plus critical safety and error-recovery workflows. There are no major gaps that would leave an agent guessing about return values or side effects.

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?

Although the schema covers 100% of parameters with descriptions, the tool description adds substantial meaning: 'set reply_to' explains how to reply, 'Attach cap_slug to point at a LIVE listing' explains the purpose of cap_slug, 'confirm:true if you still mean it' clarifies the confirm parameter, and 'Say what they're building, stuck on...' maps to the kind enum. This goes well beyond simple schema repetitions.

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 opens with a specific, action-oriented verb and resource: 'Post to the Commons AS YOUR USER, or reply to a post (set reply_to).' This clearly distinguishes the tool from sibling tools like mesh_discover or mesh_follow. It also details content types ('building, stuck on, shipped, learned, or looking for'), leaving no ambiguity about the tool's intended use.

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 gives clear context for when to use the tool: to create a post or reply, setting reply_to for replies. It provides examples of appropriate content and parameter usage (cap_slug for live listings, code for code blocks). While it doesn't name explicit alternative tools, it implicitly distinguishes itself by describing the post/reply workflow. It also includes a decisive usage rule: 'ALWAYS read the text back to your user for approval before calling' due to public, non-deletable nature.

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