list_sites

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

With no annotations, the description carries the burden and does reasonably well: it implies a read-only, permission-scoped operation ('properties the account can read') and discloses the return shape ('TSV: site_url<TAB>permission_level'). It does not cover auth requirements or pagination, but for a zero-argument read-only listing the risk surface is minimal.

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?

Two short sentences, front-loaded with what is returned first and the practical follow-up instruction second. No filler or repetition.

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 no-parameter discovery tool, everything an agent needs is present: what is listed, the permission scoping, the exact output format, and how to reuse the returned values. An output schema exists, so the TSV explanation is a small redundancy rather than a gap.

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 the baseline is 4. The schema is fully covered and there is nothing for the description to compensate for; the note about site_url is guidance for other tools, not a parameter of this one.

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?

States a specific verb and resource ('List Search Console properties') plus the scope ('the account can read') and an extra detail (permission level). The resource is unmistakably distinct from the siblings search_analytics, list_sitemaps, and inspect_url.

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?

Explicitly tells the agent the downstream use: 'Use the site_url values as-is for the site_url argument of the other tools.' That is clear context for why and when to call it, though it names no exclusions or conditions under which it should be skipped.

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