List profiles

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's job is to add context. It does so by explaining the default ephemeral temp profile and that persistent profiles preserve cookies, logins, and extensions across sessions. This adds meaningful behavioral context beyond the annotations.

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 three short paragraphs; the first sentence states the core function, and the subsequent sentences provide essential context about ephemeral vs persistent profiles and related commands. Every sentence adds value without unnecessary fluff.

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?

With no parameters and an output schema, the description still explains the behavioral context thoroughly—what persistent profiles are, how they differ from the ephemeral default, and how they fit into the profile management workflow (create/switch/return). This gives the agent all it needs to decide when to invoke list_profiles.

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 has zero parameters, so the input schema fully covers parameters (vacuously). The description adds value by explaining the concept of profiles and the active profile, which gives meaning to the tool's output. No parameter documentation is needed, so a baseline 4 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 opens with 'List persistent Chrome profiles and show which one is active,' which is a specific verb+resource+outcome and clearly distinguishes it from siblings like create_profile, use_profile, and delete_profile. It goes beyond the title by specifying the scope (persistent profiles) and the active status.

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 explains the ephemeral vs persistent profile context and explicitly references create_profile, use_profile, and use_temp_profile as related actions. This gives clear context for when listing profiles would be useful, though it could more explicitly state 'use this before switching profiles' as a direct recommendation.

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