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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description still adds real context beyond them, notably that this tool does not submit and the member keeps control of the final action. It also explains the comparative role of `posted` — surfacing every line where the reported and posted records differ. It doesn't say much about the return shape beyond that.

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 purpose, then input guidance, then the boundary condition. Six sentences, all doing work, though the 'unless scoresFrom says otherwise' clause and the Submit sentence could be tightened without losing meaning.

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 9-parameter, nested-array preparation tool with no output schema, the description covers purpose, input shape, and output intent (list of differing lines) plus the safety boundary. Minor gap: nothing is said about the return payload's structure or about date/season/matchId interplay, though the schema descriptions handle those individually.

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 100%, so the schema already documents all nine parameters, and the description's guidance on set orientation ('give the sets from the member's own side, unless scoresFrom says otherwise') largely restates what `scoresFrom`'s own description says. It does clarify intent for `posted` (a diff source) and the ordering of line data, but on balance it does not add substantial new semantics.

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: it prepares the values for the score form on the USTA NorCal league site from member-reported scores. No sibling tool touches the score-entry form, and the closing line ('Call it when someone wants to enter or check a match score on NorCal') pins the use case unambiguously.

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?

Explicit trigger given ('call it when someone wants to enter or check a match score'), plus the boundary that the Desk never acts on the USTA site, so the member or their own agent presses Submit. It stops short of naming when NOT to use it or which sibling to reach for instead, but no sibling is plausibly confusable.

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