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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile needs no restating. The description adds value beyond that by disclosing the brief's composition (events, replies owed, monitor hits), telling the agent what content to expect rather than just that it is a safe read.

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?

One sentence, front-loaded with the verb and resource, then the contents. Nothing is redundant or padded.

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 parameters, an output schema, and full annotation coverage, the definition carries little burden. It states scope (today) and contents, which is enough to invoke correctly; only a note on whose account/timezone 'today' refers to is missing, and that is minor.

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 nothing to document and the baseline applies. No parameter text is needed or expected.

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?

Specific verb ('Show') plus a specific resource ('today's brief'), with an enumeration of its three sections: next events, replies owed, monitor hits. This signals it is an aggregate dashboard rather than a single-resource fetch, which implicitly separates it from siblings like list_events, awaiting_reply and list_monitors, though those siblings are never named.

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 only implied: an agent can infer this is the overview/orientation entry point instead of calling individual list tools. There is no explicit 'use when' statement, no exclusions, and no naming of the alternatives it summarizes.

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