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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered structurally. The description adds genuinely useful behavioral context beyond that: prices are in EUR and exclude VAT, both monthly and annual billing figures are returned, Enterprise is quote-only above the largest plan, and the trial is 14 days with no card required. It does not discuss freshness of pricing data or response shape, which keeps it from a 5.

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?

One dense sentence with no throat-clearing, and the most important element (plans, limits, prices) leads. The parenthetical stacking of billing and tax qualifiers makes it slightly run-on, but every clause carries real 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?

With no output schema, the description must convey what comes back, and it does: plan tiers, user limits, EUR ex-VAT prices in two billing modes, an Enterprise quote tier, and trial terms plus signup link. What is missing is the shape of the returned data (per-plan structure, whether annual figures are totals or per-month equivalents), which matters for a pricing 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?

There is a single optional parameter with 100% schema description coverage (a fr/en answer-language enum with default 'en'), so the schema already does the work. The description says nothing about language handling or localization, so it adds no meaning over the schema. Baseline 3 applies when schema coverage is complete.

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 names the exact payload: plans with user limits, EUR prices excluding VAT on monthly and annual billing, an Enterprise quote tier, and 14-day trial terms with a signup link. That is far more specific than the bare name/title and separates it from content siblings like get_overview or get_security_and_data. It stops short of 5 only because there is no explicit verb (e.g. 'Returns...') anchoring what the tool does.

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 by the content listed, which suggests it is the pricing/plan-comparison lookup, but the description never states when to call it or when a sibling such as compare_fit or start_trial_link is the better choice. Given that a trial-signup sibling exists and the description mentions the signup link, the absence of any routing guidance is a real gap.

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