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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds genuinely useful context beyond that: results come from a public pricing page, include the page quote, and carry a 'date checked' freshness marker — notable since there is no output schema to convey this.

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 tightly written sentence with the resource and scope front-loaded and zero filler. Every clause (public prices, per-plan, quote, date checked) contributes information.

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 one-parameter read tool with no output schema, the description supplies the missing return-value context (plan prices, source quote, verification date), which is what an agent most needs here. It does not address failure behavior such as an unknown or unpriced vendor, a minor gap.

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% and the single 'vendor' parameter is documented with examples ('hubspot.com' or 'Notion'). The description only restates that one vendor is accepted, adding nothing beyond the schema, so the 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?

The description gives a specific verb+resource ('Get the public plan prices for one SaaS vendor') and even specifies the granularity of the result (per-plan prices with page quote and check date). It implicitly separates itself from multi-vendor/sibling tools by scoping to 'one' vendor, but it never names an alternative tool, so it stops short of full sibling differentiation.

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?

Usage is only implied: the 'one SaaS vendor' scoping suggests this is the single-vendor lookup rather than a broad search, which hints at when to use it versus search_saas_vendors or recent_price_changes. There is no explicit when-to-use, prerequisite, or exclusion statement.

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