List diagram icons

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

Annotations already declare this as read-only, idempotent, open-world, and non-destructive. Beyond those, the description adds useful behavioral context by saying results are grouped by vendor and that `query` filters by substring, though it does not discuss pagination or ordering within groups.

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 description is a single, front-loaded sentence with compact examples and no redundant wording. Every clause contributes to identifying the resource, its usage, and its return grouping.

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 listing tool with one optional parameter and no output schema, the description is complete enough: it explains the resource, shows valid example ids, states grouping, and documents the filter. No critical agent need is missing.

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 schema has 100% description coverage and already says `query` is a case-insensitive substring. The description restates that it filters by substring without adding new syntax, defaults, or edge-case behavior, so the 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 uses a specific verb and resource: 'List the icon ids a diagram node can use' in the `@{ icon: "..." }` expression. It gives concrete examples (aws:lambda, azure:function-apps, gcp:cloud-storage) and states the grouping, so the agent can immediately tell this apart from diagram/source/version tools.

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 intended use is clear: discover icon ids for use inside a diagram node expression, with `query` available to narrow results. It does not state when not to use the tool or name alternatives, but the use case is explicit enough for selection.

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