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

Annotations already cover readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is handled. The description adds meaningful non-annotation context: the quote is a 'hard' fee (deterministic, not an estimate), it is 'Free', and it exposes what remains of the daily cap, which signals a rate-limit/allowance dimension an agent should expect.

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?

Very short and front-loaded with the core purpose, but the telegraphic fragments ('Never: Estimate the value of a job. Free.') read as notes rather than a structured description, and the dangling 'Free' is easy to misparse.

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 does describe the return shape (hard fee plus remaining daily cap), which is the important part. It remains incomplete on parameter behavior (why mandate_token is optional) and on error/edge cases for a pricing lookup.

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%: mandate_token is documented in the schema, but capability has no description beyond maxLength 40. The description mentions 'a capability' only in passing and never explains the optional mandate_token's role or when to supply it, so it does not compensate for the coverage gap.

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 states precisely what is returned: the hard platform fee for a capability before it is called, plus the remaining daily cap. It also fences off a confusable purpose ('Never: Estimate the value of a job'), so an agent can distinguish it from valuation-style siblings. It is a noun phrase rather than an explicit verb+resource, which keeps it short of a 5.

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?

'before it is called' gives the timing condition for use, and 'Never: Estimate the value of a job' is an explicit exclusion. However, no alternative tool is named (e.g. compare, discover), so the routing guidance is clear but not fully resolved to a sibling.

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