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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail beyond the annotations by enumerating the returned fields, including valid ranges for days, hourUtc, and maxItems, and noting that channel is null when unset.

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 front-loaded with the tool's purpose and then efficiently enumerates the returned fields. It is somewhat dense, but every sentence contributes either purpose, return-value semantics, or the channel-name resolution workflow.

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?

There is no output schema, so the description must explain the return values, and it does so completely: enabled, days, hourUtc, maxItems, channel, and coverFrom are all described with ranges or null behavior. It also explains how to map channel IDs to human-readable names via list_alert_channels, leaving no significant gap for an agent.

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?

The tool takes zero parameters, so there is no parameter semantics to explain. The baseline score for a zero-parameter tool is 4, and the description appropriately focuses on return-value semantics instead.

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 read operation for a specific resource: 'Read this account's issue digest.' It also distinguishes the tool from its mutation sibling set_issue_digest_config by describing the configuration being read rather than changed.

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?

The description gives clear usage context: read the account's digest configuration. It also names a specific alternative workflow for resolving the Slack channel name: call list_alert_channels and match channelId. It does not explicitly say when not to use this tool versus set_issue_digest_config, but the read/write distinction is evident.

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