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

Annotations already declare readOnly, idempotent, non-destructive, so safety is covered. The description adds real context beyond that: the list is editorial and non-sponsored with no prices or shopping links, and in widget-capable apps a visual card is shown so the text reply should stay short and not duplicate items. That last point materially changes how an agent should respond.

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?

The trigger condition is stated twice in near-identical wording ("Use this when the user is getting a dog soon and asks what to buy or prepare" and "Use when the user is getting a dog soon, passed a test drive, or asks what to buy/prepare"). Content is front-loaded and scannable, but one sentence does not earn its place.

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, the description carries the return-value burden and does so partially: it characterizes the payload (editorial list, categorized by timing, no prices/links) and notes the widget card rendering. It never lists explicit section keys or confirms the personalization effect on output, but an agent has enough to call and present it 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?

Schema coverage is 100% with enums fully documented, so the baseline is 3. The description goes slightly beyond by explaining what the optional lifestyle inputs do ("Optional lifestyle answers personalize it (apartment, alone all day, first dog)"), mapping them to living_situation, alone_time, and experience rather than restating enum values.

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: "Builds TheDogs.app's arrival checklist for a breed," then enumerates the scope (before home, day one, first week, breed-specific sizing). It is clearly distinguishable from siblings like create_test_drive_plan or get_breed_profile, which serve different stages of the same journey.

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?

Explicit triggers ("user is getting a dog soon," "passed a test drive," "asks what to buy/prepare") plus explicit exclusions: no symptoms/emergencies/treatment (refer to vet) and no training/behavior how-tos. This leaves little ambiguity about routing.

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