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

Annotations already richly declare the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds a genuine auth-type precondition (subscription requirement) and describes the deliverables, but the 'Adds one component to an existing project' framing sits in mild tension with readOnlyHint=true, creating some ambiguity rather than fully clarifying behavior.

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 dense sentences with essentially no filler; every clause carries information. The only structural nit is that it front-loads the subscription precondition rather than the core purpose, and the deliverable list is tightly packed, but it remains efficient.

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 single-parameter, no-output-schema tool with rich annotations, the description is complete: it covers the precondition, the mutation-free generative output (files, install order, target paths, install line, providers, runtime rules), and the recipe-id branch. The only missing piece, sibling routing, is already penalized under usage guidelines.

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 single slug parameter is already documented with both examples ('button' and a recipe id such as 'supabase'). The description's note that a backend recipe id 'adds that integration' with its own files and per-app wiring adds modest meaning beyond the schema, but largely echoes the schema's own example, so the high-coverage baseline of 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 states a specific verb and resource — it 'adds one component to an existing project' — and details exactly what that yields (files in install order with target paths, the install line, providers, runtime rules), plus the recipe-id variant. It is clear on its own but never explicitly distinguishes itself from siblings like get_component, find_component, or add_screen, so it stops short of a 5.

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 only eligibility guidance is the precondition 'Needs a subscription, except for the free foundation components,' which acts as a partial when-not gate. There is no explicit routing guidance telling the agent when to pick install_component over get_component/find_component or add_screen, so usage is only implied.

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