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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantive context beyond them: the output is a dated editorial pick plus a runner-up, a sourced and dated price, and explicit anti-recommendation ('when not to take it'). With no output schema, this is the only place return shape is communicated, though latency, freshness of pricing data, and failure behavior go unmentioned.

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?

Roughly three dense sentences, front-loaded with the decision and its timing, then inputs, then returns, then routing. The nine-item category list is long but does real work by telling the agent whether its domain is covered; only marginal trimming is available.

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 six-parameter, zero-required, read-only recommendation tool with no output schema, the description supplies both the return contract and the sibling routing rule, which is the critical information. Gaps are minor: how 'existing' and 'constraints' influence the pick, and what 'full' expands to, are left entirely to the schema.

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 83%, so the schema already documents nearly every parameter, making 3 the baseline. The description reinforces that task text or a jtbd id is the input, but adds nothing about full, existing, maxMonthly, or constraints — notably 'full' and 'existing' remain semantically thin even in the schema.

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 outcome (choose a provider) plus the concrete decision context (before writing integration code) and enumerates the provider categories covered. The final clause distinguishes it from the sibling depot tool, so an agent can route without opening a schema.

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 an explicit trigger ('before writing integration code'), an explicit input mode ('send task in words or a jtbd id'), and an explicit exclusion with the alternative named ('For quotes, comparisons and audits use depot'). When-to-use, when-not, and the alternative are all present.

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