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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds meaningful behavior: resolving the missing category identifier (slug or ID) from the category list automatically. This goes beyond the annotation-provided safety profile and clarifies expected input handling.

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, front-loaded with the core purpose, and every clause adds value. It avoids repetition of schema details or annotation hints, maintaining high information density.

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 simplicity, 100% schema coverage, output schema presence, and annotations describing safety, the description fully covers what an agent needs: the core operation, parameter relationship, and how to discover categories. No notable gaps remain.

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 already describes both parameters with 100% coverage. The description adds the key semantic detail that only one is required and the other is resolved automatically, which directly informs how the agent should populate the parameters. This is useful beyond the field-level descriptions.

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 the tool's function precisely: "List topics in a specific forum category." This distinguishes it from siblings like forum_get_latest_topics or forum_search, and clearly identifies the resource (topics) and scope (specific category).

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?

It provides clear usage context: topics are listed per category, and category can be specified by slug or ID. It explicitly points to forum_list_categories for discovering categories, but does not explicitly exclude alternatives like forum_get_latest_topics for global views. This is strong guidance but lacks an explicit 'when not to use' statement.

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