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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value by listing the three returned fields in the absence of an output schema, but says nothing about pricing model, rate limits, or whether the quote is binding.

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?

A single front-loaded sentence that leads with the verb and wastes no words. It is terse to the point of under-specification, but structure and economy are good.

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 usefully names the three returned fields, which is the main thing an agent needs. However it omits how days/channel influence the quote and what channel values are valid, leaving notable gaps for a 3-parameter tool.

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 schema already documents usd (5-1000000), days (1-30, default 7) and channel. The description's listed items are actually output fields, not parameter semantics, so it adds nothing beyond the schema; baseline 3 applies.

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?

'Quote a promo' names a specific verb and resource, and the trailing list identifies what the quote returns (price per impression, estimated impressions, max chars). No sibling tool covers quoting, so cross-sibling differentiation isn't needed, though the description never defines what a 'promo' or 'channel' actually is.

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?

No statement of when to use this versus alternatives, no prerequisites, and no indication of what an agent should do with the resulting quote (e.g., feed it into a promo-creation flow). Usage is only implied by the verb 'quote'.

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