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

With readOnlyHint=false and destructiveHint=false, the annotations only partially frame behavior; the description usefully adds the silent-gap semantics (segmentIndex=-1 + bps=0 when no segment covers the moment), which an agent would otherwise misread as an error. It does not explain why an evaluation is flagged non-read-only.

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?

Front-loaded with the purpose and return value, then inputs, then the gap edge case; every clause carries information. The telegraphic parentheticals are dense but not wasteful.

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?

No output schema exists, and the description compensates by naming the returned fields and the sentinel gap case. It is a bit terse on what 'bps' resolves to and on any prerequisite checks, but it is sufficient for correct invocation.

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 already 100%, so the baseline is 3, but the description groups the options by meaning ('jobValueCents (piecewise-value)' and 'jobsPerDay (adoption-indexed)'), telling the agent when each optional input is relevant — value beyond the per-field schema text.

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 resource ('Evaluate a published RateSchedule at a moment') and names the concrete return ('the effective bps'), which distinguishes it from siblings pcc_schedule_get and pcc_schedule_publish.

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 implied rather than stated: the word 'published' hints the schedule must first exist via pcc_schedule_publish, and the optional piecewise/adoption parameters imply which schedule kinds need them. There is no explicit when-to-use-vs-alternative guidance or exclusion.

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