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

Adds substantial context beyond the annotations: the admin-role requirement, the fact that it initiates UNATTENDED RECURRING spend, and that it draws from the SAME monthly Brand Radar scan quota as run_brand_radar_scan, reducing quota for ad hoc scans. Annotations only cover safety hints; this discloses cost and side-effect behavior they don't.

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 core action and its whole-replacement semantics, then prerequisites and cost. It is dense but every sentence earns its place; the quota sentence is long but materially important for safe invocation.

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 mutation tool with no output schema, it covers action semantics, permission requirements, cost/quota side effects, and a confirmation guardrail. Nothing essential for correct invocation 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?

Schema coverage is 100%, so baseline is 3, but the description adds genuine meaning: it clarifies that the competitors list and schedule are replaced wholesale rather than merged field-by-field, which affects how an agent should populate the competitors array and scheduleInterval.

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+resource ('Creates or replaces a brand monitor') and immediately clarifies the scope: 'the whole schedule and competitor list, not single fields.' This distinguishes the upsert-full-replace semantics from sibling tools like delete_brand_monitor, list_brand_monitors, and add_competitor_monitor.

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 concrete prerequisites (admin role) and an explicit behavioral instruction ('Confirm the schedule with the user before calling'), plus context on quota competition with run_brand_radar_scan. It does not explicitly say when to prefer this over add_competitor_monitor or other siblings, so it stops short of full alternative routing.

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