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

Annotations only declare readOnlyHint=false, so the description adds real value: it discloses the ownership requirement, the auth prerequisite, and that 'blocked' closes the room (i.e. it is the destructive-ish branch). It doesn't say whether updates are reversible or what happens to fields not supplied.

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, front-loaded sentences that lead with the action and effects before prerequisites. The trailing 'Backend: murl-manage EF.' is implementation trivia that doesn't help an agent decide or invoke.

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 3-parameter mutation tool with no output schema, it covers auth, ownership, prerequisites, and the effect of each status value. It omits what the call returns and failure behavior for a non-owned domain, which an agent would still want.

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?

Schema coverage is 100% and the schema already documents per-URL keying of 'domain' and the status enum meanings. The description mostly restates those semantics, adding only a small clarification that 'blocked' closes the room, so 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 and resource ('Update a mURL DOMAIN channel') and enumerates the concrete effects (branding, claimed/blocked/open) so the agent knows exactly what changes. It is clearly distinguishable from siblings like mURL_create, mURL_delete, and mURL_list_channels.

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?

Gives an explicit precondition chain: you must own the channel and must have claimed it first via mURL_create, plus an active mosADD login session. It doesn't name explicit alternatives or when-not-to-use (e.g. use mURL_create for a first claim), so it falls short of a 5.

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