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

Annotations already declare readOnlyHint=false and openWorldHint=true, indicating a write operation. The description adds useful behavioral context by mandating duplicate checks and category lookup, which is not encoded in the annotations or schema.

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 two sentences long: first states the core purpose and variants, second provides workflow prerequisites. No wasted words, front-loaded with the primary action.

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 creation tool with full schema coverage, annotations, and an output schema, the description fully covers prerequisites and purpose. No additional return-value or error-handling detail is needed.

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?

The schema covers 100% of parameters with descriptive text (e.g., 'Topic body in Markdown', 'Call forum_list_categories first'). The tool description adds no new parameter-level detail beyond reinforcing the categoryId prerequisite, so it meets the baseline but does not exceed it.

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 clearly states the verb 'create' and the resource 'forum topic', and explicitly lists the topic types (bug report, feature request, general discussion). This distinguishes it from siblings like forum_reply and forum_search.

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 provides explicit instructions: 'Always call forum_search first to check for duplicates' and 'Call forum_list_categories to get the correct categoryId'. This clearly tells the agent when and how to prepare for the call.

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