gsc_list_sites

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

Annotations already establish readOnlyHint=true and openWorldHint=true. The description adds useful behavioral context beyond annotations: it lists the permission-level-inclusive return, the need to pass the returned string to sibling tools, and the distinct string formats for domain versus URL-prefix properties.

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 purposeful sentences with no filler. It front-loads the core action, then the critical 'call this first' guidance, then the property format details. Every sentence contributes directly to correct invocation and downstream use.

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?

Given the tool has no parameters, a read-only annotation, and an output schema, the description is complete. It covers what the tool does, why it must be called first, how its output feeds other tools, and how to recognize the two property types.

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 schema makes parameter semantics moot. The description still adds relevant semantic detail about what will be returned and how those return values will be used as site_url parameters elsewhere, which compensates well for the empty schema.

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 verb and resource: 'List the Search Console properties this Google account can read, with the permission level held on each.' It clearly differentiates this tool from siblings like gsc_list_sitemaps and gsc_search_analytics by focusing on property enumeration and access level.

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 explicitly instructs agents to 'Call this first in any session' and explains that the exact string returned is required by every other Search Console tool as site_url. This is strong, practical guidance on when and why to use the tool before alternatives.

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