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

Annotations already declare readOnly/openWorld=false/destructive=false, so the safety profile is covered. The description still adds that answers come with published sources and a link to the full page and that it is scoped to guidance (not file checks), which is useful behavior beyond the structured fields.

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 topic list is long but front-loads the trigger and every item earns its place by defining coverage scope. No filler sentences; the exclusion is placed last as a boundary marker.

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 an output schema covering return values and annotations covering safety, the description only needs to cover trigger, scope, and boundaries – all present. The brief omission of how topic vs question interact when both are supplied is minor.

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 description coverage is 100% and the enum enumerates every topic, so the schema carries the parameter burden; per calibration this is a baseline 3. The description recaps 'takes a topic or the question' but adds no syntax or format detail beyond 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 and resource ('how to design a part for FDM 3D printing') and enumerates the covered topics, so the agent knows exactly what guidance it returns. The closing line 'It does not check a specific file' distinguishes it from the check_printability sibling.

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 trigger is explicit ('Use this when someone asks how to design a part...') and the exclusion 'does not check a specific file' rules out the file-inspection use case. It never names the routing sibling by name, but the when/when-not is clear enough to select correctly.

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