Refresh segment count

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=true. The description adds useful behavioral context: it recalculates a cached count without changing membership, and it returns the refreshed count. It does not restate idempotency or permissions, but with annotations covering the safety profile this is a minor omission.

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?

The description is short, labeled, and front-loaded: Purpose, Not for, Returns, Use when. Every sentence earns its place, and the most important routing information is stated first.

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 simple single-parameter refresh operation with annotations and no output schema, the description supplies enough: purpose, the alternative, the return value, and the specific scenario for use. Nothing essential is missing.

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 description coverage is 100%, and the single parameter is documented as 'Segment UUID.' The description adds no further parameter-specific detail beyond what the schema already provides, so the baseline of 3 applies.

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 a specific verb and resource: 'Recalculate a segment's cached member count.' It explicitly distinguishes itself from the sibling plunk_compute_segment by clarifying that it 'updates the number, not who is in it,' so an agent can disambiguate without opening either 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?

It names the alternative (plunk_compute_segment) and the condition for using this tool: 'A displayed size looks stale and you only need the figure corrected.' It also states when not to use it, leaving no ambiguity about tool selection.

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