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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered structurally. The description adds genuinely useful behavioral context beyond that: partial/merge semantics ('only the keys you want to change'), global-vs-per-topic scope, and a read-before-write recommendation. It stops short of describing the response or what happens to untouched fields beyond the merge implication.

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 sentences for a 22-parameter tool, with the core action front-loaded and the caveats (partial update, read first, global scope) trailing. Dense but every clause earns its place; no filler or restatement of the title.

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 wide but shallow settings-mutation tool with full enum coverage in the schema and no output schema, the description supplies the missing operational context: partial update behavior, global scope, and the read-first workflow. Nothing critical to invoking it correctly appears absent, though the return behavior is left implicit.

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 the baseline is 3 and the schema does the heavy lifting for all 22 parameters. The description adds value by grouping the settings into human-readable categories (delivery cadence, length, technicality, depth, stance, tone, interests/avoid, language, timezone, podcast/email), which helps an agent map intent to the right keys. It doesn't add format or range detail beyond what the schema provides.

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 ('Change how and when the briefing reaches this person') and then enumerates the configurable dimensions (delivery time/days, length, technicality, depth, stance, tone, interests, language, timezone, podcast/email delivery). It explicitly distinguishes itself from siblings by naming get_information_diet for reading and tune_topic for per-topic changes.

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 operating guidance: 'Pass only the keys you want to change' (partial update), 'Read get_information_diet first', and the scoping rule that these are global settings rather than per-topic ones, with the alternative (tune_topic) named for the per-topic case. Both when-to-use and when-not-to-use are covered.

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