List WebMCP tools of the page

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful context about what is returned (hints like readOnly/consequential/untrustedContent, all frames) but says nothing about tab targeting behavior beyond the schema, error cases, or ordering.

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 dense sentences that front-load the purpose before the parenthetical protocol details. The WebMCP acronym expansion is slightly heavy but earns its place by disambiguating the standards surface being read.

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?

No output schema exists, so the description usefully enumerates the returned fields and the three hint flags. What remains missing, such as behavior when a page exposes no tools or fails to initialize, is secondary for a read-only listing call.

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 and the schema documents it at 100% coverage (tabId defaults to the session target tab, referencing tab_select). The description adds no meaning beyond that, so the baseline 3 applies.

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+resource (lists page-exposed WebMCP tools) and defines scope precisely: W3C modelContext, imperative or declarative <form toolname>, across every frame. An agent can distinguish it from sibling webmcp_call without opening the schema.

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?

No explicit when-to-use or when-not guidance, and the obvious partner tool, webmcp_call, is never named. The closest thing to guidance is the note that these tools appear as "site_*" tools, which is disclosure rather than routing advice.

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