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

Annotations already establish readOnly/idempotent/non-destructive behavior, but the description adds genuinely new traits: results are an estimate explicitly marked NOT_A_QUOTE, token counts or estimates must never be presented as facts, and the operation is free. Those are concrete behavioral disclosures beyond the structured fields.

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?

It is very short and each clause carries some signal, but the opening is a sentence fragment and the core purpose is not front-loaded in an easily parseable way. Brevity is achieved at the cost of readability.

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, two parameters at 50% description coverage, and an underspecified 'capabilities' array, the description should explain inputs and the shape of the recommendation but does not. The NOT_A_QUOTE rule is the only substantive completion.

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 only 50% and the description never mentions 'needs' or 'capabilities'. The 'needs' enum list is documented in the schema, but 'capabilities' (free-form strings, maxLength 40) is unexplained in both places, and the description adds nothing about how the two arrays drive the recommendation.

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 fragments 'Build-vs-buy next to the hard fee' convey that this tool contrasts building against buying, so the verb+resource is inferable, but the phrasing is telegraphic and never states plainly what the tool returns. It does not distinguish itself from the sibling 'quote', which appears to be the closest alternative.

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?

'Never: Present a token count or an estimate as a fact' is a presentation rule for the output, not guidance on when to invoke this tool versus 'quote' or 'discover'. 'Free' signals cost but nothing tells the agent what triggers a comparison call.

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