asset_capabilities

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

Annotations already declare readOnlyHint and idempotentHint. The description adds 'Read-only; no network,' reinforcing safety and disclosing environmental constraints. This aligns with and supplements annotations without contradiction.

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?

Two concise sentences: the first states functionality, the second gives usage instruction and behavioral notes. No superfluous words; information is front-loaded and efficiently presented.

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 read-only capability check with one optional parameter and no output schema, the description fully covers what the agent needs: what the tool does, when to call it, and environmental constraints. The return format is implied (list of modes), which is sufficient.

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 sole parameter asset_type has 100% schema description coverage, and the description repeats the schema's explanation verbatim ('Narrow the modes-by-asset-type section to one type'), adding no new meaning. Baseline 3 is appropriate.

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 indicates the tool reports which execution modes the server can run, listing three specific modes (inline_svg, external_prompt_only, api). This verb+resource purpose is distinct from sibling tools that generate or ingest assets.

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 explicitly says 'Call before offering the user options,' providing clear guidance on when to use. It does not explicitly say when not to use or name alternatives, but the context of sibling tools implies it is a preliminary check before mode selection.

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