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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is low. The description adds non-structured context the annotations cannot convey: this tool renders an interactive UI and only works in MCP Apps-capable clients, and it returns the same data as build_bom. It does not say what happens in a non-supporting client, keeping it from a 5.

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 short sentences, zero filler, with the interactive-rendering constraint and the build_bom equivalence front-loaded. Every sentence carries information an agent needs.

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?

An output schema exists, so return values need no explanation, and the annotations carry the safety profile. The description covers client compatibility and data equivalence, leaving only the undocumented 'choices' parameter and the non-supporting-client fallback as minor gaps.

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 description adds no meaning about build_id or the nested 'choices' map beyond what the schema labels. At 50% schema description coverage, 'choices' is an undocumented nested object with no explanation of its keys or purpose anywhere, so the description fails to compensate for the gap.

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 ('composes the BOM for a reference build') plus the rendering behavior ('interactive view'), and explicitly distinguishes itself from the sibling build_bom by noting it is 'Same data as build_bom' but presented as a view. An agent can select between the two without opening either 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 a clear selection condition: use this in clients that support MCP Apps, and the 'Same data as build_bom' note implies build_bom is the fallback for other clients. It stops short of stating the alternative explicitly ('use build_bom when the client lacks app support'), so it is strong but not complete.

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