list_blocks

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

The readOnlyHint annotation already establishes this is a safe read, but the description goes further by explaining the shared-reference semantics (one edit updates every page using them) and enumerating the returned fields (documentId, type, name, per-locale status, folderId). That return-shape disclosure is genuinely valuable given there is no output schema.

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, front-loaded with the core purpose, then the return shape, then the edit path, then the exclusion. Every sentence carries distinct information with no repetition of the name or structured fields.

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 single-parameter, read-only list tool with no output schema, the description covers purpose, the crucial shared-vs-inline distinction, the returned fields, and the follow-up editing path. Nothing essential for correct invocation is missing.

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?

There is only one parameter (site) and schema description coverage is 100%, so the schema already documents it fully, including the multisite default behavior and the list_sites pointer. The description adds only the implicit 'this site's' scoping; baseline 3 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?

States a specific verb (list) and resource (shared/reusable blocks), and immediately disambiguates from inline blocks — a real distinction an agent would otherwise miss. It also names the representative subtypes (banners, forms, CTAs), making it distinguishable from siblings like list_pages and list_globals.

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?

Provides a clear exclusion (inline blocks are not listed here) and routes the agent to the correct follow-up tools for modification (get_content/update_content on documentId). It does not explicitly contrast against other list tools such as list_globals or list_pages, so it stops short of full when/when-not guidance.

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