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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds value beyond them by detailing the shape of the return (a catalog with type, label, category, input/output ports, settings, description), which tells the agent what it will actually get back.

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 core statement and alternative routing are front-loaded, and the Args block is efficient. A few sentences (the canvas/strategy philosophy and 'three years a run') are atmospheric rather than operational, costing it a perfect score.

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 read-only, two-optional-parameter list tool with no output schema, the description covers purpose, return shape, filtering, and sibling relationships. Nothing critical is missing, though it could state ordering/pagination behavior of the returned catalog.

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 0%, so the description must carry both parameters, and it does: category is described as an optional filter with a concrete example list, and search is described as a case-insensitive substring matched against block type and label. That is more than the schema offers, though it lacks e.g. format constraints or behavior when both are supplied.

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 — 'List the cards' — and immediately resolves ambiguity by defining a primitive as a card and enumerating what each catalog entry contains (type, label, category, ports, settings, description). It also distinguishes itself from build_circuit (assembles cards) and run_circuit (executes), so an agent can tell the three apart 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?

The description frames this as the discovery step feeding build_circuit ('build_circuit puts these cards together in the chat, step by step') and points to run tools for data/results, giving clear contextual routing. It stops short of an explicit 'call this before build_circuit' instruction or any exclusions, so it is strong but not a full when/when-not statement.

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