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

Annotations only declare readOnlyHint=true; the description goes well beyond by naming the underlying endpoint (GET /api/limits), fixing the unit convention ('Sizes are bytes'), and disclosing a conditional output shape when BREWPAGE_OWNER_TOKEN is set (extra reach and ownerMaxTtlDays fields). That conditional-response behavior is exactly the kind of context annotations cannot convey.

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?

Front-loaded verb and resource, then a dense but purposeful enumeration; the byte-unit note and the owner-token clause each add real information. The literal 'GET /api/limits' is arguably redundant for an agent but is small overhead in an otherwise tight two-sentence definition.

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?

With no output schema and no parameters, the description carries the return-value burden itself and does so by listing every reported limit category. An agent knows what it will get back and when the response will be expanded, which is sufficient to call this correctly.

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?

Zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate. The description correctly spends no words on arguments.

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?

Specific verb + resource ('Get the current BrewPage upload limits') followed by an enumeration of exactly what limits are reported. No sibling tool does anything similar, so an agent can immediately tell this is the limits-introspection tool rather than a read of content (get_page, get_json, get_stats).

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: an agent can infer it should call this before publish_file/publish_html to learn size and extension constraints, but the description never says so. There are no explicit exclusions or named alternatives, and no stated prerequisites (it doesn't say no auth is required for the base call).

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