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

Annotations only carry the generic mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false). The description goes well beyond them: it discloses that omitting method is a free preview ('nothing is charged'), that credits charge the first month at connect time then recur monthly, that card methods return a redirect_url requiring the user to pay before connecting, and warns 'Spends the workspace's money.'

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?

Front-loaded with purpose, then a 'When to use' hook, then compact bullets for each payment mode. Every sentence carries actionable information (trigger, cost, timing, next step); no 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?

With no output schema, the description supplies the return-relevant facts an agent needs: the preview lists prices and methods, card flows return redirect_url, and the credits path continues straight to the connect tool. For a money-spending tool with only 3 params, this is complete.

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 baseline is 3, but the description adds real meaning beyond the schema text: it explains the consequences of each method value (charge timing for credits, redirect flow for card) and that omitting method is a no-charge preview. Only in_workspace semantics are left to 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?

States a specific verb+resource (choose how the workspace pays for a paid channel) and links it directly to the sibling connect tools by name (channels.connect_telegram_bot, channels.connect). An agent can immediately tell this apart from the handful of other channels_* 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?

Explicit trigger condition: 'a connect tool answered billing_required.' It then enumerates the three modes (omit method / credits / card) with the follow-up action for each ('then call the connect tool again'), leaving nothing to inference.

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