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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: default scope (all five sectors), how invalid sector names are handled, and what the date omission does.

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 what the tool returns, then the valid sector set, then the branching behaviour of the two filters. Dense but every clause is functional; the only cost is that the sector enumeration bulks up the middle.

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 an output schema present, return values need no explanation, and the description fully covers input semantics, defaults, and edge cases (invalid sector names, date-omitted behaviour). Nothing an agent needs in order to call this correctly 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 0%, so the description must carry the full load, and it does: it enumerates every valid sector id with its display label, clarifies that 'sectors' narrows the default set of five, and specifies the YYYY-MM-DD date format plus its default (latest note). A reader needs nothing further to supply valid arguments.

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 concrete verb and resource — retrieving sector notes from 'The 07:00 Brief' — and enumerates the five sectors with human-readable labels. It does not explicitly contrast itself with siblings like get_morning_brief or list_recent_briefs, so sibling differentiation is left to inference.

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?

Gives clear conditional behavior: no date returns the latest note per sector, a date (YYYY-MM-DD) returns notes published that day, and names outside the five valid sectors are reported as unavailable rather than silently dropped. It stops short of naming an alternative tool for when a broader brief is wanted.

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