list_profiles

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

Annotations already declare readOnlyHint=true, and the description reinforces that with 'Read-only.' It adds valuable non-obvious behaviors: the owner-allowed visibility scoping via the 'API' column, the exact list of returned fields, and that the proxy password is hidden. This exceeds the minimum bar set by the read-only annotation.

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 sentences with no filler: purpose is front-loaded, the field list is compactly enumerated, and the critical 'call it first' usage note lands at the end. Every sentence earns its place.

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 0-param, read-only list tool with no output schema, the description is complete: it states what is listed, the visibility constraint, every returned field, and the security-relevant detail that passwords are hidden. An agent has everything needed to call it correctly and interpret its result.

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 explain about arguments. Per the baseline for 0-param tools, a 4 is appropriate; the description needs only to describe the operation and result, which it does thoroughly.

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 opens with a specific verb+resource: 'List the browser profiles the owner has allowed for the agent.' It further distinguishes itself from siblings by clarifying scope ('other profiles are invisible here'), marking itself read-only, and positioning itself as the prerequisite for all other profile 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 description gives explicit when-to-use guidance: 'Call it first: every other tool takes a profile name exactly as listed here.' This clearly points to the tool as the entry point for all profile operations. It does not, however, name a specific alternative for a given condition or state an explicit 'when not to use' case, so it stops short of a 5.

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