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

readOnlyHint=true already tells the agent this is a safe read, so the description's main added value is the 'published' scope constraint. It does not address password-protected access behavior, error responses, or whether unpublished drafts are reachable, all of which would be useful for a fetch-by-ID call.

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?

One sentence with no filler, and the verb plus keying are front-loaded. It is perhaps slightly under-specified rather than padded, so it lands just under the top mark.

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 simple read-only lookup with a fully described 3-parameter schema, readOnlyHint, and no output schema to explain, the description covers what an agent needs to make the call. Only the protected-document and not-found paths are left unstated, a minor 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?

Schema description coverage is 100%, so namespace, id, and password are already documented structurally. The description mentions namespace and ID by name but adds no format, case-sensitivity, or password-handling semantics beyond the schema, 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?

The description gives a specific verb ('Fetch') and resource ('BrewPage JSON document') plus the keying ('by namespace and ID'), which is enough to separate it from get_page and get_kv. It stops short of explicitly contrasting with those siblings, keeping it below a 5.

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?

Usage is only implied: the word 'published' signals the document must already be published, which is real guidance, but there is no statement of when to choose this over get_page, get_kv, or search_gallery, and no mention of prerequisites or failure modes.

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