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

Beyond the annotations, the description discloses replacement semantics (whole list overwritten, [] wipes it), immediate effect with no sync required, and the write-scope auth requirement (mcp:write). These are consistent with readOnlyHint=false and idempotentHint=true: repeating the same list yields the same state. The full-list overwrite is mildly in tension with destructiveHint=false, but the description explicitly warns about it, so the agent is not misled.

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 with the action and the constraints, and every clause carries real information (limits, normalization, replacement rule, auth, trigger). It is dense to the point of being a single run-on sentence, and the appended Portuguese sentence duplicates content with essentially no added signal.

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 two-parameter config setter with no output schema, the definition covers limits, normalization, replacement behavior, timing, auth scope and when to invoke it. Nothing an agent needs in order to call it correctly 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?

At 100% schema coverage the baseline is 3; the description adds genuine semantics — terms are lower-cased and de-duplicated, must be 2–40 characters (clarifying the schema's looser items maxLength of 60), and a query counts as branded when it contains one of them. Only the 'site' parameter gets no added meaning beyond the schema, keeping it from a 5.

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?

Names a specific verb (replaces) and resource (branded terms of one Search Console property) and explains the downstream effect: the brand filter, get_breakdown, get_branded_performance and the branded shape of analyze_query_shapes. That lets an agent distinguish it from set_bing_key/set_ga4_property and from the read-only branded siblings without opening a 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?

Gives explicit triggers — 'use it when check_connection lists no_branded_terms or brand=branded was rejected' — and states the calling convention (send the full list, [] clears) so the agent knows not to send a partial patch. It also names the exact precondition check_connection that precedes it, which is unusually actionable.

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