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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description contributes real domain context by defining what 'verified' means (builder proof validating against the Arc mainnet builder registry), but says nothing about result volume, pagination, or whether verification is re-checked live.

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?

A single tight sentence with no filler, and the distinguishing criterion is placed immediately. It is under-specified rather than verbose, so the brevity costs it little here.

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 zero-parameter read-only filter tool with no output schema, the description conveys the selection rule but not the return shape (list of projects? names? addresses?) or ordering. Adequate but leaves an agent guessing about what it will actually receive.

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 tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; the description does not need to compensate for any schema 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?

The description names a specific selection criterion — projects whose builder proof validates against the Arc mainnet builder registry — which is more than a restatement of the title. However it is a bare noun phrase with no verb, so it never states whether the tool lists projects, returns a count, or returns a boolean, and it draws no boundary against the many sibling listing tools (arc_apps, arc_new_apps, arc_project_scope).

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?

There is no when-to-use guidance, no mention of alternatives, and no indication of how this differs from arc_apps or arc_project_scope. The agent must infer from the name alone that this is the filtered 'verified builders' variant.

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