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

Annotations already cover the safety profile (readOnly=false, destructive=false, openWorld=false), so the bar is lower. The description still adds real behavioral value beyond them: a hard anti-hallucination rule about image URLs and a structural example showing the expected payload shape.

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?

Three tightly packed sentences: purpose, selection criterion, then a compact example plus the critical sourcing caveat. Every sentence earns its place and the selection condition is front-loaded before the example.

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 9-parameter insertion tool with full schema coverage and no output schema, the description supplies what the structured fields don't: when to pick this question type, the payload example, and the image-sourcing rule. It is adequate, though it could note the after/position chaining intent that the schema only hints at.

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%, so all nine parameters (including after/position chaining rules and storageId) are already documented; the baseline of 3 applies. The inline example adds marginal shape clarity for the images array but no syntax detail the schema does not already carry.

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 ('Insert a picture choice question') and immediately scopes it against the large family of sibling question-insertion tools by declaring the condition that selects this one: 'when choices are inherently visual (products, designs, photos).' An agent can distinguish it from editor_insertRadioQuestion or editor_insertImage without opening any schema.

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?

Gives clear positive selection criteria (visual choices) and an explicit sourcing constraint ('use images the user uploaded or URLs they provided — never invent or guess image URLs'). It does not name alternative siblings or state when *not* to use it, so it falls short of the 5-level explicit routing seen in the calibration example.

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